GW-B5600CY-1 G-Shock Men’s Watch

Product Information

Specifications

• Model: MA2309-EA
• Operation Guide: 3540
• Water Resistance: Yes
• Water Resistance Level: Up to 20 Atmospheres

Product Usage Instructions

Operating Precautions

Water Resistance: The watch is marked with WATER RESIST or WATER
RESISTANT on the back cover. The level of water resistance
determines the activities you can safely engage in while wearing
the watch.

Under Daily Use:

or skin
diving)
10BAR| Hand washing, rain| Safe, water-related work, swimming, windsurfing (not skin
diving)
20BAR| Hand washing, rain| Safe, water-related work, swimming, windsurfing, skin
diving

Do not use the watch for scuba diving or any other type of
diving that requires air tanks. Watches without WATER RESIST or
WATER RESISTANT markings are not protected against sweat. Avoid
exposing such watches to excessive sweat, moisture, or direct
splashing with water.

Before Getting Started…

General Guide: Familiarize yourself with the watch’s buttons and
functions as described in the user manual.

Indicators: Understand the various indicators displayed on the
watch, indicating modes, settings, and other information.

Navigating Between Modes: Learn how to switch between different
modes to access specific features and settings.

Charging: Follow the instructions to charge the watch before
initial use or when the battery is low.

Viewing the Face in the Dark: Discover how to activate the
backlight for clear visibility in low-light conditions.

Useful Features: Explore additional features and functionalities
offered by the watch.

Linking with a Phone

Getting Ready: Prepare your phone and watch for the mobile link
feature.

Auto Time Adjustment: Allow the watch to automatically adjust
its time based on your phone’s time settings.

Configuring Reminder Settings: Set up reminders on your watch
using the mobile link feature.

Configuring World Time Settings: Customize world time settings
on your watch using the mobile link feature.

Phone Finder: Use your watch to locate your phone when it is
nearby.

Configuring Watch Settings: Adjust various settings on your
watch using the mobile link feature.

Changing the Home City: Modify the home city setting on your
watch using the mobile link feature.

Summer Time Setting: Enable or disable summer time (daylight
saving time) on your watch using the mobile link feature.

Checking the Watch Charge Level: Monitor the battery level of
your watch through the mobile link feature.

Recording Your Current Location (TIME & PLACE): Save your
current location on your watch using the mobile link feature.

Connection: Establish a stable connection between your phone and
watch for seamless functionality.

Time Adjustment

Time Adjustment Using a Time Signal: Learn how to adjust the
time on your watch using a time signal.

Overview: Understand the process of time adjustment and the
options available.

Appropriate Signal Reception Location: Find the ideal location
for receiving accurate time signals.

Time Signal Reception Ranges: Know the range within which your
watch can receive time signals.

Auto Time Calibration Signal Receive: Enable automatic time
calibration signal reception on your watch.

Manual Time Calibration Signal Receive: Manually initiate time
calibration signal reception on your watch.

Receive Level Indicator: Interpret the receive level indicator
to determine the signal reception quality.

Signal Reception Precautions: Follow precautions to ensure
successful time signal reception.

Using Watch Operations to Adjust the Time Setting: Utilize watch
operations to manually adjust the time setting.

Using the Watch in a Medical Facility or Aircraft: Understand
the guidelines for using the watch in specific environments.

World Time

Using CASIO WATCHES to Configure World Time City Settings: Set
up world time city settings on your watch.

Checking World Time: Access world time information on your
watch.

World Time City Setting: Modify world time city settings on your
watch.

Swapping Your Home Time and World Time: Swap the displayed time
between your home city and world time city.

Alarm

Using CASIO WATCHES to Configure Alarm Settings: Set up alarms
on your watch.

Configuring Alarm Settings: Customize alarm settings according
to your preferences.

Enabling the Hourly Time Signal: Activate the hourly time signal
feature on your watch.

Turning Off an Alarm or the Hourly Time Signal: Disable specific
alarms or the hourly time signal feature.

Moving to Another Time Zone

Learn how to adjust the time on your watch when traveling to a
different time zone.

Stopwatch

Measuring Elapsed Time: Use the stopwatch function to measure
the elapsed time of an event.

Measuring a Split Time: Record split times during a stopwatch
measurement.

Timing the First and Second Place Finishers: Utilize the
stopwatch to time multiple participants and determine finishing
order.

Timer

Using CASIO WATCHES to Configure Timer Settings: Set up timers
on your watch.

Setting the Countdown Start Time: Set the start time for
countdown timers on your watch.

Using the Timer: Activate and utilize countdown timers for
various purposes.

Reminder

Creating a Reminder: Create reminders on your watch for
important events or tasks.

Checking Reminder Notifications: Receive notifications for set
reminders on your watch.

Other Settings

Changing the Date Display Format: Customize the date display
format on your watch.

Specifying the Day of the Week Language: Select the language for
displaying the day of the week on your watch.

Enabling the Button Operation Tone: Enable or disable the button
operation tone on your watch.

Configuring Power Saving Function Settings: Adjust power-saving
function settings to optimize battery life.

Resetting Watch Settings: Reset all settings on your watch to
their default values.

Other Information

City Table: Access a table containing various cities and their
corresponding time zones.

Summer Time Table: View a table displaying information about
summer time (daylight saving time) changes.

Supported Phones: Check the compatibility of your phone with the
mobile link feature.

Specifications: Review the technical specifications of your
watch.

Copyrights and Registered Copyrights: Understand the copyright
information related to the watch.

FAQ

Q: Can I use this watch for scuba diving?

A: No, this watch is not suitable for scuba diving or any other
type of diving that requires air tanks.

Q: Is the watch protected against sweat?

A: Watches without WATER RESIST or WATER RESISTANT markings on
the back cover are not protected against sweat. Avoid using such
watches under conditions where they will be exposed to large
amounts of sweat or moisture, or direct splashing with water.

MA2309-EA

© 2023 CASIO COMPUTER CO., LTD.
Watch Operation Guide 3540

Contents
Precautions
Operating Precautions User Maintenance Battery Mobile Link Precautions
Before Getting Started…
General Guide Indicators Navigating Between Modes Charging Viewing the Face in the Dark Useful Features
Linking with a Phone
Getting Ready Auto Time Adjustment Configuring Reminder Settings Configuring World Time Settings Phone Finder Configuring Watch Settings Changing the Home City Summer Time Setting Checking the Watch Charge Level Recording Your Current Location (TIME & PLACE) Connection
Connecting with a Phone Disconnecting from Your Phone Unpairing If you purchase another phone

Time Adjustment
Time Adjustment Using a Time Signal Overview Appropriate Signal Reception Location Time Signal Reception Ranges Auto Time Calibration Signal Receive Manual Time Calibration Signal Receive Receive Level Indicator Signal Reception Precautions
Using Watch Operations to Adjust the Time Setting Using the Watch in a Medical Facility or Aircraft
World Time
Using CASIO WATCHES to Configure World Time City Settings Checking World Time World Time City Setting Swapping Your Home Time and World Time
Alarm
Using CASIO WATCHES to Configure Alarm Settings Configuring Alarm Settings Enabling the Hourly Time Signal Turning Off an Alarm or the Hourly Time Signal
Moving to Another Time Zone
Stopwatch
Measuring Elapsed Time Measuring a Split Time Timing the First and Second Place Finishers

Timer
Using CASIO WATCHES to Configure Timer Settings Setting the Countdown Start Time Using the Timer
Reminder
Creating a Reminder Checking Reminder Notifications
Other Settings
Changing the Date Display Format Specifying the Day of the Week Language Enabling the Button Operation Tone Configuring Power Saving Function Settings Resetting Watch Settings
Other Information
City Table Summer Time Table Supported Phones Specifications Copyrights and Registered Copyrights
Troubleshooting

OPUM-H

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Watch Operation Guide 3540

Precautions

Operating Precautions

Water Resistance
The information below applies to watches with WATER RESIST or WATER RESISTANT marked on the back cover.

Water Resistance Under Daily Use

Marking on watch front or on back cover
Example of Daily Use

No BAR mark

Hand washing, rain

Yes

Water-related work, swimming

No

Windsurfing

No

Skin diving

No

Enhanced Water Resistance Under Daily Use 5 Atmospheres

Marking on watch front or on back cover
Example of Daily Use

5BAR

Hand washing, rain

Yes

Water-related work, swimming Yes

Windsurfing

No

Skin diving

No

10 Atmospheres

Marking on watch front or on back cover
Example of Daily Use

10BAR

Hand washing, rain

Yes

Water-related work, swimming Yes

Windsurfing

Yes

Skin diving

Yes

20 Atmospheres

Marking on watch front or on back cover
Example of Daily Use

20BAR

Hand washing, rain

Yes

Water-related work, swimming Yes

Windsurfing

Yes

Skin diving

Yes

Do not use your watch for scuba diving or other types of diving that requires air tanks.
Watches that do not have WATER RESIST or WATER RESISTANT marked on the back cover are not protected against the effects of sweat. Avoid using such a watch under conditions where it will be exposed to large amounts of sweat or moisture, or to direct splashing with water.
Even if a watch is water resistant, note the usage precautions described below. Such types of use reduce water resistance performance and can cause fogging of the glass. Do not operate the crown or buttons while your watch is submersed in water or wet. Avoid wearing your watch while in the bath. Do not wear your watch while in a heated swimming pool, sauna, or any other high temperature/high humidity environment. Do not wear your watch while washing your hands or face, while doing housework, or while performing any other task that involves soaps or detergents.
After submersion in seawater, use plain water to rinse all salt and dirt from your watch.
To maintain water resistance, have the gaskets of your watch replaced periodically (about once every two or three years).
A trained technician will inspect your watch for proper water resistance whenever you have its battery replaced. Battery replacement requires the use of special tools. Always request battery replacement from your original retailer or from an authorized CASIO service center.
Some water-resistant watches come with fashionable leather bands. Avoid swimming, washing, or any other activity that causes direct exposure of a leather band to water.

The inside surface of the watch glass may fog when the watch is exposed to a sudden drop in temperature. No problem is indicated if the fogging clears up relatively quickly. Sudden and extreme temperature changes (such as coming into an air conditioned room in the summer and standing close to an air conditioner outlet, or leaving a heated room in the winter and allowing your watch to come into contact with snow) can cause it to take longer for glass fogging to clear up. If glass fogging does not clear up or if you notice moisture inside of the glass, immediately stop using your watch and take it to your original retailer or to an authorized CASIO service center.
Your water-resistant watch has been tested in accordance with International Organization for Standardization regulations.
Band
Tightening the band too tightly can cause you to sweat and make it difficult for air to pass under the band, which can lead to skin irritation. Do not fasten the band too tightly. There should be enough room between the band and your wrist so you can insert your finger.
Deterioration, rust, and other conditions can cause the band to break or come off of your watch, which in turn can cause band pins to fly out of position or to fall out. This creates the risk of your watch falling from your wrist and becoming lost, and also creates the risk of personal injury. Always take good care of your band and keep it clean.
Immediately stop using a band if you even notice any of the following: loss of band flexibility, band cracks, band discoloration, band looseness, band connecting pin flying or falling out, or any other abnormality. Take your watch to your original retailer or to a CASIO service center for inspection and repair (for which you will be charged) or to have the band replaced (for which you will be charged).

2

Watch Operation Guide 3540

Temperature
Never leave your watch on the dashboard of a car, near a heater, or in any other location that is subject to very high temperatures. Do not leave your watch where it will be exposed to very low temperatures. Temperature extremes can cause your watch to lose or gain time, to stop, or otherwise malfunction.
Leaving your watch in an area hotter than +60 °C (140 °F) for long periods can lead to problems with its LCD. The LCD may become difficult to read at temperatures lower than 0 °C (32 °F) and greater than +40 °C (104 °F).
Impact
Your watch is designed to withstand impact incurred during normal daily use and during light activity such as playing catch, tennis, etc. Dropping your watch or otherwise subjecting it to strong impact, however, can lead to malfunction. Note that watches with shock-resistant designs (G-SHOCK, BABY-G, G-MS) can be worn while operating a chain saw or engaging in other activities that generate strong vibration, or while engaging in strenuous sports activities (motocross, etc.)
Magnetism
Though a digital watch normally is not affected by magnetism, very strong magnetism (from medical equipment, etc.) should be avoided because it can cause malfunction and damage to electronic components.
Electrostatic Charge
Exposure to very strong electrostatic charge can cause your watch to display the wrong time. Very strong electrostatic charge even can damage electronic components.
Electrostatic charge can cause the display to go blank momentarily or cause a rainbow effect on the display.

Chemicals
Do not allow your watch to come into contact with thinner, gasoline, solvents, oils, or fats, or with any cleaners, adhesives, paints, medicines, or cosmetics that contain such ingredients. Doing so can cause discoloration of or damage to the resin case, resin band, leather, and other parts.
Storage
If you do not plan to use your watch for a long time, thoroughly wipe it free of all dirt, sweat, and moisture, and store it in a cool, dry place.
Resin Components
Allowing your watch to remain in contact with other items or storing it together with other items for long periods while it is wet can cause color on resin components to transfer to the other items, or the color of the other items to transfer to the resin components of your watch. Be sure to dry off your watch thoroughly before storing it and make sure it is not in contact with other items.
Leaving your watch where it is exposed to direct sunlight (ultraviolet rays) for long periods or failure to clean dirt from your watch for long periods can cause it to become discolored.
Friction caused by certain conditions (strong external force, sustained rubbing, impact, etc.) can cause discoloration of painted components.
If there are printed figures on the band, strong rubbing of the printed area can cause discoloration.
Leaving your watch wet for long periods can cause fluorescent color to fade. Wipe the watch dry as soon as possible after it becomes wet.
Semi-transparent resin parts can become discolored due to sweat and dirt, and if exposed to high temperatures and humidity for long periods.
Daily use and long-term storage of your watch can lead to deterioration, breaking, or bending of resin components. The extent of such damage depends on usage conditions and storage conditions.

Leather Band
Allowing your watch to remain in contact with other items or storing it together with other items for long periods while it is wet can cause the color of the leather band to transfer to the other items or the color of the other items to transfer to the leather band. Be sure to dry off your watch thoroughly with a soft cloth before storing it and make sure it is not in contact with other items.
Leaving a leather band where it is exposed to direct sunlight (ultraviolet rays) for long periods or failure to clean dirt from a leather band for long periods can cause it to become discolored.
CAUTION: Exposing a leather band to rubbing or dirt can cause color transfer and discoloration.
Metal Components
Failure to clean dirt from metal components can lead to formation of rust, even if components are stainless steel or plated. If metal components exposed to sweat or water, wipe thoroughly with a soft, absorbent cloth and then place the watch in a well-ventilated location to dry.
Use a soft toothbrush or similar tool to scrub the metal with a weak solution of water and a mild neutral detergent, or with soapy water. Next, rinse with water to remove all remaining detergent and then wipe dry with a soft absorbent cloth. When washing metal components, wrap the watch case with kitchen plastic wrap so it does not come into contact with the detergent or soap.
Bacteria and Odor Resistant Band
The bacteria and odor resistant band protects against odor generated by the formation of bacteria from sweat, which ensures comfort and hygiene. In order to ensure maximum bacteria and odor resistance, keep the band clean. Use an absorbent soft cloth to thoroughly wipe the band clean of dirt, sweat, and moisture. A bacteria and odor resistant band suppresses the formation of organisms and bacteria. It does not protect against rash due to allergic reaction, etc.
Liquid Crystal Display
Display figures may be difficult to read when viewed from an angle.
Note that CASIO Computer Co., Ltd. assumes no responsibility for any damage or loss suffered by you or any third party arising through the use of your watch or its malfunction.

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Watch Operation Guide 3540

User Maintenance
Caring for Your Watch
Remember that you wear your watch next to your skin, just like a piece of clothing. To ensure your watch performs at the level for which it is designed, keep it clean by frequently wiping with a soft cloth to keep your watch and band free of dirt, sweat, water and other foreign matter.
Whenever your watch is exposed to sea water or mud, rinse it off with clean fresh water.
For a metal band or a resin band with metal parts, use a soft toothbrush or similar tool to scrub the band with a weak solution of water and a mild neutral detergent, or with soapy water. Next, rinse with water to remove all remaining detergent and then wipe dry with a soft absorbent cloth. When washing the band, wrap the watch case with kitchen plastic wrap so it does not come into contact with the detergent or soap.
For a resin band, wash with water and then wipe dry with a soft cloth. Note that sometimes a smudge like pattern may appear on the surface of a resin band. This will not have any effect on your skin or clothing. Wipe with a cloth to remove the smudge pattern.
Clean water and sweat from a leather band by wiping with a soft cloth.
Not operating a watch crown, buttons, or rotary bezel could lead to later problems with their operation. Periodically rotate the crown and rotary bezel, and press buttons to maintain proper operation.

Dangers of Poor Watch Care
Rust
Though the metal steel used for your watch is highly rust-resistant, rust can form if your watch is not cleaned after it becomes dirty. Dirt on your watch can make it impossible for oxygen to come into contact with the metal, which can lead to breakdown of the oxidization layer on the metal surface and the formation of rust.
Rust can cause sharp areas on metal components and can cause band pins to fly out of position or to fall out. If you ever notice any abnormality immediately stop using your watch and take it to your original retailer or to an authorized CASIO service center.
Even if the surface of the metal appears clean, sweat and rust in crevasses can soil the sleeves of clothing, cause skin irritation, and even interfere with watch performance.
Premature Wear
Leaving sweat or water on a resin band or bezel, or storing your watch an area subject to high moisture can lead to premature wear, cuts, and breaks.
Skin Irritation
Individuals with sensitive skin or in poor physical condition may experience skin irritation when wearing a watch. Such individuals should keep their leather band or resin band particularly clean. Should you ever experience a rash or other skin irritation, immediately remove your watch and contact a skin care professional.

Battery
The special rechargeable battery used by your watch is not intended to be removed or replaced by you. Use of a rechargeable battery other than the special one specified for your watch can damage your watch.
The rechargeable (secondary) battery is charged when the solar panel is exposed to light, so it does not require regular replacement as the primary battery requires. Note, however, that long use or operating conditions can cause the capacity or charging efficiency of the rechargeable battery to deteriorate. If you feel that the amount of operation provided by charging is too short, contact your original retailer or CASIO service center.

4

Watch Operation Guide 3540

Mobile Link Precautions
Legal Precautions
This watch complies with or has received approval under the radio laws of various countries and geographical areas. Using this watch in an area where it does not comply with or has not received approval under applicable radio laws may be a criminal offense. For details, visit the CASIO Website. https://world.casio.com/ce/BLE/
Use of this watch inside of aircraft is restricted under the aviation laws of each country. Be sure to follow the instructions of airline personnel.
Precautions when using Mobile Link
When using this watch in combination with a phone, keep the watch and phone close to each other. A range of two meters is recommended as a guideline, but the local environment (walls, furniture, etc.), the structure of a building, and other factors may require a much closer range.
This watch can be affected by other devices (electrical devices, audio-visual equipment, office equipment, etc.) In particular, it can be affected by operation of a microwave oven. The watch may not be able to communicate normally with a phone if a microwave oven is operating nearby. Conversely, this watch may cause noise in radio reception and the video image of a TV.
Bluetooth of this watch uses the same frequency band (2.4 GHz) as wireless LAN devices, and use of such devices in close proximity of this watch may result in radio interference, slower communication speeds and noise for the watch and the wireless LAN device, or even communication failure.

Stopping Radio Wave Emission by This Watch
The watch is emitting radio waves whenever e is flashing or displayed. In addition, the watch also connects phone automatically four times a day to adjust its time setting.
When in a hospital, on an aircraft, or in any other area where the use of radio waves is not allowed, use the operation below to stop radio wave generation.
Stopping Radio Wave Generation Press any button to terminate the Bluetooth connection.

Connected

Disconnected

Disabling Auto Time Adjustment Configure CASIO WATCHES settings to disable time adjustment between the watch and phone. l Using the Watch in a Medical Facility or Aircraft

5

Watch Operation Guide 3540

Before Getting Started…
This section provides an overview of the watch and introduces convenient ways it can be used.
Watch Features Phone Linking
The watch supports connection and communication with a Bluetooth capable phone. Solar Charging Sunlight and artificial light generate electricity for watch operation as it charges. Time Signal Reception The watch receives a radio signal containing time information and uses it to keep its time setting accurate. World Time The current time can be displayed for any one of 39 cities around the globe, as well as for UTC (Coordinated Universal Time). You can select up to five cities in the World Time Mode. Alarm An alarm sounds whenever a time specified by you is reached. Stopwatch The stopwatch measures elapsed time in units of one second (1/100 second for the first hour) up to 24 hours. Timer Countdown from a start time specified by you. An alarm sounds when the countdown reaches zero.
Note
The illustrations included in this operation guide have been created to facilitate explanation. An illustration may differ somewhat from the item it represents.

General Guide

ADay of the week BMonth, day CHour, minute, second
A button Holding down this button for at least two seconds in any mode displays the setting screen.
B button Press to turn on illumination.
C button Each press cycles between watch modes. In any mode, hold down this button for at least one second to return to the Timekeeping Mode.
D button Pressing this button while any setting screen is displayed will change the setting.

Indicators

ADisplayed while there is a Bluetooth connection between the watch and a phone.
BDisplayed while Power Saving is enabled.
CDisplayed while Auto Light is enabled.
DDisplayed after time adjustment using time signal reception or connection with a phone was successful. The [RCVD] indicator will disappear in the cases below. After you use watch operations to change Home City settings (time and date, city, summer time) After the watch switches between standard time and summer time After a time signal receive operation fails After a phone-based time adjustment operation fails
EDisplayed during p.m. times while 12-hour timekeeping is being used.
FDisplayed while the watch is indicating summer time.
GDisplayed when battery power is low.
HDisplayed while an alarm is turned on.
IDisplayed while the hourly time signal is enabled.
JDisplayed while the button operation tone is disabled.
KDisplayed while the snooze alarm is turned on.

6

Watch Operation Guide 3540

Navigating Between Modes
Each press of (C) cycles between watch modes. In any mode, hold down (C) for at least one
second to return to the Timekeeping Mode.
Timekeeping Mode

$ Timer Mode

$ World Time Mode

Charging
This watch runs on power supplied from a rechargeable (secondary) battery that is charged by a solar panel. The solar panel is integrated into the face of the watch, and power is generated whenever the face is exposed to light.
Charging the Watch When you are not wearing the watch, put it in a location where it is exposed to bright light.

Low Battery A low battery will cause [LOW] to flash and will disable the functions below. Time signal reception Illumination Sounds (alarm, etc.) Connection with a phone
If the charge level drops even further, [CHG] will flash. If this happens, all functions are disabled.

$ Stopwatch Mode

$ Alarm Mode

$

Connecting with a Phone Hold down (C) for at least three seconds to connect with a phone. To disconnect, press any button.

Before connection

After connection

$

Any button

While you are wearing the watch, make sure that its face (solar panel) is not blocked from light by the sleeve of your clothing. Power generation efficiency is reduced even when the face of the watch is blocked only partially.

YES

NO

Important!
Some light sources and environments can cause the watch to become extremely hot during charging, which creates the risk of burn injury and damage to internal watch components. Avoid charging the watch under conditions like the ones described below, where the temperatures may exceed 60 °C (140 °F). On the dashboard of a vehicle parked in the sun Near incandescent lamps, camera lights, halogen lamps, or other sources of heat In locations exposed to direct sunlight for long periods and other hot locations

Dead Battery The digital display will go blank if the battery goes dead. Memory data is lost, and watch settings are returned to their initial factory defaults.
Important!
Should the battery go low or go dead, expose the face (solar panel) to light as soon as possible.
Exposing the watch to light while its battery is dead will cause [CHG] to start flashing. Keep the watch exposed to light until the current time appears on the display.
Note
If [R] is flashing, it means that all functions, except for timekeeping, are disabled due to high momentary battery power consumption. l [R] is flashing on the digital display.

7

Watch Operation Guide 3540

Charging Time Guidelines
The table below shows guidelines for approximate charging times.

Charging Times Required for 1 Day of Operation

Light Level (Lux)
50,000 10,000 5,000
500

Approximate Charging Time
8 minutes 30 minutes 48 minutes
8 hours

Charge Recovery Times Sunny day, outdoors (50,000 lux)

Dead battery n Medium charge Medium charge n High charge High charge n Full charge

3 hours 36 hours 10 hours

Sunny day, near a window (10,000 lux)

Dead battery n Medium charge Medium charge n High charge High charge n Full charge

10 hours 134 hours 36 hours

Overcast day, near a window (5,000 lux)

Dead battery n Medium charge Medium charge n High charge High charge n Full charge

16 hours 217 hours 58 hours

Indoor fluorescent lighting (500 lux)

Dead battery n Medium charge Medium charge n High charge High charge n Full charge

211 hours –

Note

Actual charging time depends on the charging environment, watch settings, and other factors.

Power Saving Function Leaving the watch in a dark location for about one hour between the hours of 10 p.m. and 6 a.m. will cause the display to go blank, and the watch to enter Level 1 power saving. If the watch is left in this condition for six or seven days, the watch will enter Level 2 power saving.
Power Saving Level 1 : Digital display goes blank to save power. The watch can connect with a phone at this level.
Power Saving Level 2 : Digital display goes blank to save power. All functions are disabled.
Recovering from Power Saving Operation Use one of the operations below to exit power saving. Press any button. Move the watch to a bright location. Trigger auto light by angling the watch
towards your face.
Note
The watch will not enter power saving in the cases below. Alarm Mode While in the Stopwatch Mode While in the Timer Mode
You can enable or disable Power Saving. l Configuring Power Saving Function Settings
Note that the watch also may enter power saving if its face is blocked from light by your sleeve while you are wearing it.

Viewing the Face in the Dark
The watch has a light that illuminates the face for viewing in the dark. To illuminate the face manually Press (B) to turn on illumination. Illumination will turn off automatically if an
alarm starts to sound.
Important!
Frequent use of illumination will run down the battery.
Note
Display illumination is disabled when any one of the conditions below exists. Alarm, timer alert, or other beeper sounding Time calibration reception in progress
To illuminate the face when Auto Light is enabled
If Auto Light is enabled, face illumination will turn on automatically whenever the watch is positioned at an angle of 40 degrees or more.
40 degrees or more

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Watch Operation Guide 3540

Important!
Auto Light may not operate properly when the watch is at a horizontal angle of 15 degrees or greater from horizontal as shown in the illustration below.
Auto Light may operate unintentionally and run down the battery if the watch is blocked from light by your sleeve.
Electro-static charge or magnetism can interfere with proper auto light operation. If this happens, try lowering your arm and then angle it towards your face again.
When moving the watch you may note a slight rattling sound. This is due to operation of the auto light switch, which determines the current orientation of the watch. It does not indicate malfunction.
Note
Auto Light is disabled when any one of the conditions below exists. Alarm, timer alert, or other beeper sounding Time calibration reception in progress

Specifying the Illumination Duration You can select either two seconds or four seconds as the illumination duration.
1. Enter the Timekeeping Mode. l Navigating Between Modes
2. Hold down (A) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.
Home City

Useful Features
Pairing the watch with your phone makes a number of the watch’s features easier to use. Auto time adjustment l Auto Time Adjustment
12:30

3. Press (C) 12 times to display [LIGHT].

Selection of More Than 300 World Time cities l Configuring World Time Settings

4. Press (D) to select an illumination duration. [2]: 2-second illumination [4]: 4-second illumination

Recording of Anniversaries and Appointments l Configuring Reminder Settings

Configuring the Auto Light Setting
1. Enter the Timekeeping Mode. l Navigating Between Modes
2. Hold down (B) for at least three seconds to toggle Auto Light between enabled and disabled. [LT] is displayed while Auto Light is enabled.
On

5. Press (A) to exit the setting screen.

Note
Auto Light is disabled while [CHG] is shown on the display.

In addition, a number of other watch settings can be configured using your phone.
To transfer data to a watch and to configure settings, you first need to pair the watch with your phone. l Getting Ready
Your phone needs to have the CASIO “CASIO WATCHES” app installed to pair with the watch.

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Watch Operation Guide 3540

Linking with a Phone
While there is a Bluetooth connection between the watch and phone (Mobile Link), the watch’s current time setting is adjusted automatically. You can also change the watch’s other settings.
Note
This function is available only while CASIO WATCHES is running on the phone.
This section describes watch and phone operations. X : Watch operation Y : Phone operation
Getting Ready
To use your watch in combination with a phone, you first need to pair them. Perform the steps below to pair the watch with a phone.
A Install the app on your phone. In Google Play or the App Store, search for the “CASIO WATCHES” phone app and install it on your phone.
B Configure Bluetooth settings. Enable the phone’s Bluetooth.
Note
For details about setting procedures, see your phone documentation.

C Pair the watch with a phone. Before you can use the watch in combination with a phone, you first need to pair them.
1. Move the phone to be paired with close to (within one meter of) the watch.
2. Y Tap the “CASIO WATCHES” icon.
3. Y Tap the of the “My Watch” tab.
4. Y Perform the operation shown on the phone screen to register the watch to the CASIO WATCHES phone app.
5. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash. When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display. If pairing fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode. Perform the pairing procedure again from the beginning.

Pairing started

Pairing complete

Note
The first time you start up CASIO WATCHES phone app, a message will appear on your phone asking if you want to enable location information acquisition. Configure settings to allow background use of location information.

Auto Time Adjustment
Your watch will connect with a phone at preset times each day and adjust its time settings automatically.
Using This Function Your watch adjusts its time setting four times a day according to a preset schedule. If you leave your watch in the Timekeeping Mode, it will perform the adjustment operation automatically as you go about your daily life, without any operation required by you.
12:30
Important!
The watch may not be able to perform auto time adjustment under the conditions described below. While the watch is too far away from its paired phone While communication is not possible due to radio interference, etc. While the phone is updating its system While the CASIO WATCHES phone app is not running on the phone
Note
If there is a World Time City specified with the CASIO WATCHES phone app, its time will also be adjusted automatically.
The watch will connect with the phone and perform auto time adjustment at around 12:30 a.m., 6:30 a.m., 12:30 p.m. and 6:30 p.m. The connection is automatically terminated after auto time adjustment is complete.
Time signal auto receive will be performed if there has been no auto time adjustment based on connection between the watch and phone for more than one day.

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Watch Operation Guide 3540

Triggering Immediate Time Adjustment
The watch’s time setting will be adjusted automatically whenever you establish a connection between the watch and a phone. Whenever you want to trigger immediate time adjustment, perform the procedure below to connect with a phone.

1. X Enter the Timekeeping Mode. l Navigating Between Modes
2. Move the phone close to (within one meter of) the watch.
3. X Press (D).
[TIME] flashes to indicate that the watch has started the connection operation. Once the watch and phone are connected, [OK] will appear, and then the watch will adjust its time setting based on information from the phone.
At this time your current location is recorded by your phone.

Trying to connect

After time adjustment

Note
The connection is terminated automatically after time adjustment is complete.
If time adjustment fails for some reason, [ERR] will appear.
[RCVD] flashes when the receive operation starts, and [RCVD] stops flashing after it is complete.

Configuring Reminder Settings

After you use CASIO WATCHES to create reminders, appointments, anniversaries, or other events you need to remember, you can check them on the watch.
You can have up to five reminders registered.

1. Y Tap the “CASIO WATCHES” icon.
2. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash.
When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display.
If connection fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode.

Trying to connect

Connected

3. Y Follow the instructions that appear on the screen to configure reminder settings. You can input up to 18 alphanumeric characters as a reminder title.
Note
To prevent the appointments from being displayed on the watch, use CASIO WATCHES to turn off the reminder setting.

Configuring World Time Settings
Specifying a World Time City with the CASIO WATCHES phone app causes the watch’s World Time City to change accordingly. Settings can be configured to perform auto summer time switching for the World Time City.
Note
The CASIO WATCHES phone app World Time lets you select from among approximately 300 cities as the World Time City.
You can use the CASIO WATCHES phone app to configure settings for user cities that are not included in the watch’s built-in World Time Cities. You must use the CASIO WATCHES phone app to select a user city as your World Time City.

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Watch Operation Guide 3540

To select a World Time City

1. Y Tap the “CASIO WATCHES” icon.
2. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash.
When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display.
If connection fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode.

Trying to connect

Connected

3. Y Perform the operation shown on the phone screen. The World Time setting will be reflected on the watch.

Creating a User City
In addition to the approximately 300 cities available with CASIO WATCHES, you can specify a location on an on-screen map and create a user city.

1. Y Tap the “CASIO WATCHES” icon.
2. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash.
When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display.
If connection fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode.

Trying to connect

Connected

3. Y Perform the operation shown on the phone screen. The World Time setting will be reflected on the watch.
Note
You can have up to five locations registered as user cities.
You can assign a name up to 18 characters long to each user city.

Configuring the Summer Time Setting

1. Y Tap the “CASIO WATCHES” icon.
2. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash.
When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display.
If connection fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode.

Trying to connect

Connected

3. Y Perform the operation shown on the phone screen to select a summer time setting.
“Auto” The watch switches between standard time and summer time automatically.
“OFF” The watch always indicates standard time.
“ON” The watch always indicates summer time.
Note
While the summer time setting is “Auto”, the watch will switch between standard time and summer time automatically. You do not need to switch between standard time and summer time manually. Even if you are in an area that does not observe summer time, you can leave the watch’s summer time setting as “Auto”.
Changing the time setting manually with a watch operation will cancel auto standard time/summer time switching.
For information about summer time periods, refer to the “Summer Time Table” or CASIO WATCHES.

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Watch Operation Guide 3540

Swapping Your World Time and Home Time

1. Y Tap the “CASIO WATCHES” icon.
2. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash.
When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display.
If connection fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode.

Trying to connect

Connected

Phone Finder
You can use phone finder to trigger a tone on the phone to make it easy to find. The tone is forced to sound even if the phone is in vibrate mode.
Important!
Do not use this function in areas where phone call tones are restricted.
The tone sounds at a high volume. Do not use this function when listening to phone output over earphones.

1. X If the watch is connected with a phone, press any button to terminate the connection.

Connected

Disconnected

Configuring Watch Settings

Alarm time, timer start time, and other settings can also be configured using CASIO WATCHES.

1. Y Tap the “CASIO WATCHES” icon.
2. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash.
When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display.
If connection fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode.

Trying to connect

Connected

3. Y Perform the operation shown on the phone screen to swap your Home Time with your World Time.
Note
Auto time adjustment does not work for 24 hours after swapping of the Home Time and World Time.

2. X If the watch is in any mode besides the Timekeeping Mode, hold down (C) for at least one second to enter the Timekeeping Mode.

3. X Hold down (D) for at least five seconds. Release the button when e and [FIND] start to flash.
The phone will sound a tone when it establishes a connection with the watch.
It will take a few seconds before the phone tone sounds.

Getting ready to connect with phone

Sounding phone alert sound

3. Y Select the setting you want to change and then perform the operation shown on the phone screen.

4. X Press any button to stop the tone.
You can press any watch button to stop the phone tone only during the first 30 seconds after it starts to sound.

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Watch Operation Guide 3540

Changing the Home City Summer Time Setting

1. Y Tap the “CASIO WATCHES” icon.
2. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash.
When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display.
If connection fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode.

Trying to connect

Connected

3. Y Perform the operation shown on the phone screen to change your Home City summer time setting.

Checking the Watch Charge Level

Use the procedure below to check the current charge level with CASIO WATCHES.

1. Y Tap the “CASIO WATCHES” icon.
2. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash.
When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display.
If connection fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode.

Trying to connect

Connected

3. Y Use CASIO WATCHES to check the charge level.

Recording Your Current Location (TIME & PLACE)
While traveling or otherwise on the go, you can use the procedure below to record your current location, along with the time and date, on your phone. Recorded location information can be viewed on a CASIO WATCHES map while the watch is connected with your phone. Recording Your Current Location
1. X Enter the Timekeeping Mode. l Navigating Between Modes
2. X When you are in the location you want to record, press (D). This records, in phone memory, your latitude and longitude and the current date and time, and displays [OK] on the watch. At this time the time settings of your phone and watch will be synced with each other.
Viewing a Recorded Location on a Map
1. Y Tap the “CASIO WATCHES” icon. 2. Y Perform the operation shown on the
phone screen to view recorded location information.
Note
You can use CASIO WATCHES to delete recorded location information.

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Watch Operation Guide 3540

Connection

Connecting with a Phone
Your watch can connect with a phone that is paired with it. If the watch is not paired with the phone you
want to connect with, refer to the information below and pair them. l C Pair the watch with a phone.
Connecting with a Phone
1. Move the phone close to (within one meter of) the watch.
2. X Hold down (C) for at least three seconds. Release the button when e and [CNCT] start to flash. When a connection is established between the watch and phone, e and [CNCT] will stop flashing and remain on the display. If connection fails for some reason, [ERR] will appear on the display momentarily and then the watch will return to the Timekeeping Mode.

Trying to connect

Connected

Important!
If you have problems establishing a connection, it could mean that CASIO WATCHES is not running on your phone. On your phone’s home screen, tap the “CASIO WATCHES” icon. After the app starts up, hold down the watch’s (C) button for at least three seconds.

Note
The connection will be terminated if you do not perform any operation on the watch or phone for a fixed amount of time. To specify the connection limit time, perform the following operation with CASIO WATCHES: “Watch settings” n “Connection time with the app”. Next, select a setting of 3 minutes, 5 minutes, or 10 minutes.

Disconnecting from Your Phone
Pressing any button will terminate a Bluetooth connection and return to the Timekeeping Mode.

Connected

Disconnected

Deleting Pairing Information from the Watch
1. X Hold down (C) for at least one second to enter the Timekeeping Mode.
2. X Hold down (A) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.
Home City
3. X Press (C) twice. This causes the seconds to flash.
Seconds
4. X Hold down (B) for at least three seconds. This will cause the [PAIR] and [CLR] indicators to alternate on the display. Release the button when only [CLR] is displayed. This deletes the pairing information from the watch and returns to the timekeeping display.

Unpairing Unpairing the watch from a phone requires both CASIO WATCHES phone app and watch operations.
Deleting Pairing Information from the CASIO WATCHES phone app
1. Y Tap the “CASIO WATCHES” icon.
2. Y Perform the operation shown on the phone screen to unpair.

5. X Press (A) to return to the Timekeeping Mode.
If you purchase another phone
You need to perform the pairing operation whenever you want to establish a Bluetooth connection with a phone for the first time. l Deleting Pairing Information from the
Watch l C Pair the watch with a phone.

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Watch Operation Guide 3540

Time Adjustment
Your watch can obtain date and time information by connecting with a phone and by receiving time signals, which it uses to adjust its settings.
Important!
When you are on an aircraft or in any other location where radio signals may cause problems, enable the watch’s Airplane Mode to disable connection with your phone. l Using the Watch in a Medical Facility or Aircraft

Referring to the information below, configure the time setting in accordance with the method that suits your own lifestyle.
Do you use a phone? Time adjustment by connecting with your phone is recommended. l Auto Time Adjustment
12:30
Can you receive a time signal in your area? While the watch’s Home Time City setting is one where a time signal can be received, the watch’s time and day settings can be adjusted in accordance with the signal. l Time Signal Reception Ranges l Setting a Home City

Time Adjustment Using a Time Signal
Overview The watch’s time and day settings can be configured in accordance with a received time calibration signal.
Important!
In order to make it possible for the current time setting to be adjusted correctly based on time calibration signal reception, you need to specify the time zone where you are using the watch.
If the watch was unable to connect with a phone even once for time adjustment during the previous day while connection with a phone is being used, it will automatically try to receive a time calibration signal.
Note
Areas where time calibration signal reception is supported are limited. When the watch is in an area where time calibration signal reception is not possible, connect with a phone to adjust time and day settings. l Time Signal Reception Ranges

Other than the above.
If you are unable to connect with a phone and are unable to receive a time signal, you can perform watch button operations to adjust its time setting. l Using Watch Operations to Adjust the
Time Setting

16

Watch Operation Guide 3540

Appropriate Signal Reception Location A time calibration signal can be received while the watch is near a window. Position the watch so its 12 o’clock side is facing the window. Keep metal objects away from the watch. Do not move the watch. Do not perform any operation on the watch.
12 o’clock
Note
You may experience time calibration signal reception problems in the areas described below. Among or near buildings While riding in a vehicle Near household appliances, office machines, mobile phones, etc. On a construction site, in an airport, or any other location where radio wave interference occurs Near high-voltage lines In mountainous areas or behind a mountain

Time Signal Reception Ranges
Japan (JJY) The Japan time signal radio stations are located on Mt. Otakadoya in Fukushima and Mt. Hagane in Fukuoka/Saga. The reception range of the Japanese time signals is approximately 1,000 km from each transmission station.
China (BPC) The China time signal radio station is located in Shangqiu, Henan Province, China. The reception range of the Chinese time signal is approximately 1,500 km from the transmission station.
United States (WWVB) The United States time signal radio station is located in Fort Collins, Colorado. The reception range of the U.S. time signal is approximately 3,000 km from the transmission station.
U.K. (MSF)/Germany (DCF77) The U.K. time signal radio station is located in Anthorn, Cumbria. The German time signal radio station is located in Mainflingen, southeast of Frankfurt. The reception range of the U.K. and German time signals is approximately 1,500 km from each transmission station.
Note
Even if you are within the normal reception range of a time calibration signal, reception may be made impossible by the following factors: geographic contours, weather, the season, the time of day, wireless noise.
A time calibration signal cannot be received while the city selected as your Home City is one that does not support signal reception.

Auto Time Calibration Signal Receive An automatic time calibration signal receive operation is performed and the time and day settings are adjusted between midnight and 5:00 a.m. Once a signal receive operation is successful, no more auto receive operations are performed that day.
1. Place the watch near a window or some other location appropriate for signal reception. [RCVD] flashes while time signal reception is in progress. When the receive operation is successful, the time and day settings are adjusted automatically, and the [RCVD] indicator appears.
Note
Reception takes anywhere from about two minutes to about 10 minutes. It can take as long as 20 minutes.
Manual Time Calibration Signal Receive
1. Place the watch near a window or some other location appropriate for time signal reception.
2. Enter the Timekeeping Mode. l Navigating Between Modes
3. Hold down (D) for at least two seconds until [RCVD] flashes. This indicates that the receive operation has started. After the receive operation is complete, the watch’s time and day settings will be adjusted accordingly.

Receive level indicator
The level indicator shows the signal level ([L1], [L2], [L3]) while a receive operation is in progress. l Receive Level Indicator

17

Watch Operation Guide 3540

Note
When a receive operation is successful, [RCVD] will appear, and the time and day settings will be adjusted automatically.
If a receive operation fails for some reason, [RCVD] disappears and [ERR] appears on the display. To return to the unadjusted timekeeping display, press any button.
The receive operation takes anywhere from about two minutes to about 10 minutes. It can take as long as 20 minutes.
Time calibration signal reception is better at night than during the day.
Receive Level Indicator
While a receive operation is in progress, its current status is indicated on the display as shown below. Use the level indicator to find a location where signal reception is stable.

Receive level indicator

Unstable

Stable

Note
It takes about 10 seconds for time signal reception conditions to stabilize.
Reception conditions are affected by weather, the time of day, the surrounding environment, etc.

Signal Reception Precautions
When the watch is unable to adjust its time in accordance with a calibration signal for some reason, average timekeeping accuracy is within ±15 seconds per month.
Note that an internal decoding process the watch performs after it receives a signal may cause the time setting to be slightly off (by less than one second).
Time calibration signal reception is not possible under the conditions described below. While battery power is low While the watch is in the Stopwatch Mode, Timer Mode, or Alarm Mode When the watch is at Level 2 power saving While a timer countdown operation is in progress While auto time adjustment is disabled While the Home City area setting is one where time signal reception is not possible While the watch is outside the time signal reception range
When the receive operation is successful, the time and/or day settings will be adjusted automatically. Summer time will not be applied correctly in the case described below. When the summer time start date and time, end date and time, or other rules are changed by authorities
As of January 2023, China does not observe summer time. If China starts to observe summer time in the future, the time displayed by the watch for China may not be correct.

Using Watch Operations to Adjust the Time Setting
If your watch cannot connect with a phone for some reason, you can use watch operations to adjust date and time settings. Setting a Home City Use the procedure in this section to select a city to use as your Home City. If you are in an area that observes summer time, you can also configure a summer time setting.
Note
The initial factory default summer time setting for all cities is [AUTO]. In many cases, the [AUTO] setting lets you use the watch without switching between summer time and standard time.
1. Enter the Timekeeping Mode. l Navigating Between Modes
2. Hold down (A) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.
Home City
3. Use (B) and (D) to change the Home City setting. Holding down (B) or (D) scrolls through settings at high speed. For details refer to the information below. l City Table
4. Press (C).

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Watch Operation Guide 3540

5. Use (D) to select a summer time setting. Each press of (D) cycles through available settings in the sequence shown below. [AUTO] The watch switches between standard time and summer time automatically. [OFF] The watch always indicates standard time. [ON] The watch always indicates summer time.
6. Press (A) to complete the setting operation.
Note
While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation.
Setting the Time/Date
1. Enter the Timekeeping Mode. l Navigating Between Modes
2. Hold down (A) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.
Home City

3. Keep pressing (C) until the setting you want to change is flashing. Each press of (C) moves the flashing to the next setting in the sequence shown below.
Home City
Summer time
Seconds
Hours
Minutes
Year
Month
Day
12/24-hour timekeeping
Date display format
Day of the week language
Operation tone enable/disable

4. Configure the date and time settings. To reset the seconds to 00: Press (D). 1 is added to the minutes when the current count is between 30 and 59 seconds. For all the other settings, use (B) and (D) to change the flashing setting. Holding down (B) or (D) scrolls through settings at high speed.
5. Repeat steps 3 and 4 to select time and date settings.
6. Press (A) to complete the setting operation.
Note
While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation.
Switching between 12-hour and 24hour Timekeeping
You can specify either 12-hour format or 24hour format for the time display.
1. Enter the Timekeeping Mode. l Navigating Between Modes
2. Hold down (A) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.
Home City

Illumination duration

Auto time adjustment

Power Saving

19

Watch Operation Guide 3540

3. Press (C) eight times.
This causes [12H] or [24H] to flash on the display.

4. Press (D) to toggle the setting between [12H] (12-hour timekeeping) and [24H] (24-hour timekeeping).

12-hour timekeeping

24-hour timekeeping

5. Press (A) to complete the setting operation.
Note
While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation.

Using the Watch in a Medical Facility or Aircraft
Whenever you are in a hospital, on an aircraft, or in any other location where auto time calibration signal receive or connection with a phone may cause problems, you can perform the procedure below to disable such operations. To re-enable auto time adjustment, perform the same operation again.
1. Enter the Timekeeping Mode. l Navigating Between Modes
2. Hold down (A) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.
Home City
3. Press (C) 13 times. This displays [RECEIVING].

World Time
You can view the current time in 39 cities (39 time zones), and UTC (Coordinated Universal Time) time.
Using CASIO WATCHES to Configure World Time City Settings
If the watch is paired with a phone, you can also use CASIO WATCHES to set the World Time city. l Configuring World Time Settings
Note World Time cities that can be selected
only by using CASIO WATCHES cannot be selected using watch operations.

4. Press (D) to toggle between the auto time adjustment settings. [OFF]: Auto time adjustment disabled. [On]: Enable auto time adjustment.
5. Press (A) to complete the setting operation.

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Watch Operation Guide 3540

Checking World Time
1. Enter the World Time Mode. l Navigating Between Modes Entering the World Time Mode causes a World Time number and city name to appear first. After that, the display will appear as shown below.
World Time number
World Time Home City time
Pressing (A) displays the city for the displayed time.
Use (D) to scroll through World Time cities in numeric order.
World Time City Setting
You can specify up to five cities as your World Time favorites. If you are in an area that observes summer time, you can also enable or disable summer time.
Note
The initial factory default summer time setting for all cities is [AUTO]. In many cases, the [AUTO] setting lets you use the watch without switching between summer time and standard time.
1. Enter the World Time Mode. l Navigating Between Modes
2. Use (D) to display the World Time number whose setting you want to configure.
World Time number

3. Hold down (A) for at least two seconds. This causes [WT] to flash on the display.
4. Use (B) and (D) to display the city you want to specify as a World Time City. Holding down (B) or (D) scrolls through settings at high speed.
5. If you want to change the summer time setting, press (C).
6. Use (D) to select a summer time setting. [AUTO] The watch switches between standard time and summer time automatically. [OFF] The watch always indicates standard time. [ON] The watch always indicates summer time.
7. Press (A) to complete the setting operation.
Note
While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation.
While [UTC] is selected as the city, you will not be able to change or check the summer time setting.
If you select a World Time City with the CASIO WATCHES phone app and then change to a different city with a watch operation, the CASIO WATCHES city information is deleted from the watch. l Configuring World Time Settings

Swapping Your Home Time and World Time
In the World Time mode, press (A) and (B) at the same time to swap your Home City time with your World Time. Example: To swap your Home City (Tokyo) with your World Time City (New York)

Before swapping Tokyo time

After swapping New York time

New York time

Tokyo time

Note
This function comes in handy when you need to move to another time zone. For details about how to use it, go to the section below. l Moving to Another Time Zone

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Watch Operation Guide 3540

Alarm
The watch will beep when the alarm time is reached. You can configure up to four standard daily alarms, and one daily alarm with snooze. The hourly time signal causes the watch to beep every hour on the hour. Snooze causes the alarm to sound up to
seven times, at five-minute intervals. The alarm sound is muted in the cases
described below. When battery power is low When watch is at Level 2 power saving
l Power Saving Function

3. Hold down (A) for at least two seconds. Release the button when the hours digits start to flash. While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation.
Alarm hour
4. Use (B) and (D) to change the hour setting. Holding down (B) or (D) scrolls through settings at high speed. If you are using 12-hour timekeeping, [P] indicates p.m.

Testing the alarm In the Alarm Mode, hold down (D) to sound the alarm.
To stop the alarm Pressing any button while the beeper is sounding stops it. Snooze causes the alarm to sound up to seven times, at five-minute intervals. To cancel a snooze alarm, turn [SNZ] off. l Turning Off an Alarm or the Hourly Time
Signal
Note
A beeper sounds for 10 seconds when an alarm time is reached.
The watch will automatically return from the Alarm Mode to the Timekeeping Mode if you do not perform any operation for about two or three minutes.

Using CASIO WATCHES to Configure Alarm Settings
If the watch is paired with a phone, you can also use CASIO WATCHES to set alarms. l Configuring Watch Settings
Configuring Alarm Settings
1. Enter the Alarm Mode. l Navigating Between Modes
2. Use (D) to display the alarm screen (alarm number [1] to [4] or [SNZ]) whose setting you want to change.
Alarm number

5. Press (C). This causes the minutes digits to flash.

Alarm minute

6. Use (B) and (D) to set the minute setting.

7. Press (A) to exit the setting screen.

(alarm) is shown on the

display while an alarm is turned on.

Alarm time

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Watch Operation Guide 3540

Enabling the Hourly Time Signal
1. Enter the Alarm Mode. l Navigating Between Modes
2. Use (D) to display the hourly time signal screen ([SIG]).

1. Enter the Alarm Mode. l Navigating Between Modes
2. Use (D) to scroll through the alarm ([1] to [4], [SNZ]) and hourly time signal ([SIG]) screens until the one you want to turn off is displayed.
Alarm number or hourly time signal

Moving to Another Time Zone
Use the procedure below to easily change day and time settings of the watch to a destination location.
Before Boarding
1. Configure the World Time to the current time at your destination.

3. Press (A) to toggle the hourly time signal between enabled and disabled.

(hourly time signal) is shown on

the display while the hourly time signal is turned on.

Turning Off an Alarm or the Hourly Time Signal
To stop an alarm or the hourly time signal from sounding, perform the steps below to turn it off. To have an alarm or hourly time signal
sound again, turn it back on.
Note
Indicators are displayed while any of the alarms or the hourly time signal is turned on.
The applicable indicators are not displayed while all of the alarms are turned off and/or the hourly time signal is turned off.
Alarm

3. Press (A) to turn off the displayed alarm or the hourly time signal.
Each press of (A) toggles between on and off.

Turning off an alarm causes

(alarm) to disappear from the display. Turning off the hourly time signal

causes

(hourly time signal) to

disappear.

Note

If

(alarm) is still displayed

after you turn off an alarm, it means that at least one of the other alarms is still turned on. To turn off all of the alarms, repeat steps 2 and 3 until the

(alarm) indicator is no

longer displayed.

Current time
Destination time
l Using CASIO WATCHES to Configure Settings
l Using Watch Operations to Configure Settings
2. Disable auto time adjustment.
l Using the Watch in a Medical Facility or Aircraft

Snooze Hourly time signal

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Watch Operation Guide 3540

After Arriving
1. Swap the origin time zone time with the destination time zone time.

Before swapping

After swapping

World Time Destination

World Time Origin

l Using CASIO WATCHES to Configure Settings
l Using Watch Operations to Configure Settings
2. Enable auto time adjustment. l Using the Watch in a Medical Facility or Aircraft
3. Adjust the time setting. l Triggering Immediate Time Adjustment

Stopwatch
The stopwatch measures elapsed time in 1/100-second units for the first hour, and in 1second units after that for up to 23 hours 59 minutes 59 seconds (24 hours).
Measuring Elapsed Time
1. Enter the Stopwatch Mode. l Navigating Between Modes
2. Use the operations below to measure elapsed time.
Start

Measuring a Split Time

1. Enter the Stopwatch Mode. l Navigating Between Modes
2. Use the operations below to measure elapsed time.
Pressing (A) displays the elapsed time from the start of a race up to the point when you pressed the button (split time).
D Start

A Split

A Split release

D Stop

Elapsed time is shown in 1/100-second units for the first hour of the measurement. After the first hour, elapsed time is shown in one-second units.

First hour

After first hour

Stop

Resume

Stop

Elapsed time is shown in 1/100-second units for the first hour of the measurement. After the first hour, elapsed time is shown in one-second units.

First hour

After first hour

Minutes, seconds, 1/100 seconds

Hour, minute, second

3. Press (A) to reset the measurement time to all zeros.

Minutes, seconds, 1/100 seconds

Hour, minute, second

3. Press (A) to reset the measurement time to all zeros.

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Watch Operation Guide 3540

Timing the First and Second Place Finishers

1. Enter the Stopwatch Mode. l Navigating Between Modes
2. Use the operations below to measure elapsed time.
D Start

A 1st Finisher*

D 2nd Finisher*

• This displays the time of the first finisher.
  Elapsed time is shown in 1/100-second units for the first hour of the measurement. After the first hour, elapsed time is shown in one-second units.

First hour

After first hour

Minutes, seconds, 1/100 seconds

Hour, minute, second

3. Press (A) to display the time of the second finisher.
4. Press (A) to reset the measurement time to all zeros.

Timer
The timer counts down from a start time specified by you. A beeper sounds when the end of the countdown is reached. The beeper is muted when battery power is
low.
Using CASIO WATCHES to Configure Timer Settings
If the watch is paired with a phone, you can also use the CASIO WATCHES phone app to set the timer start time. l Configuring Watch Settings
Setting the Countdown Start Time
The countdown start time can be set in 1second units up to 24 hours. If a timer countdown operation is in
progress, reset the timer to its current start time before performing this operation. l Using the Timer 1. Enter the Timer Mode.
l Navigating Between Modes 2. Hold down (A) for at least two seconds.
This causes the hours digits to flash.

4. Press (C). This causes the minutes digits to flash.
Minutes
5. Use (B) and (D) to change the timer minutes setting.
6. Press (C). This causes the seconds digits to flash.
Seconds
7. Use (B) and (D) to change the seconds setting.
8. Press (A) to exit the setting screen. Note While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation. Setting a start time of [0:00 00] will perform a countdown of 24 hours.

Hours
3. Use (B) and (D) to change the timer hours setting. Holding down (B) or (D) scrolls through settings at high speed.

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Watch Operation Guide 3540

Using the Timer
1. Enter the Timer Mode. l Navigating Between Modes
Hour, minute, second
2. Use the operations below to perform a timer operation.
D Start
(Countdown starts)
D Pause
D Resume
(Time up)
A beeper will sound for 10 seconds to let you know when the end of a countdown is reached.
You can reset a paused countdown to its start time, by pressing (A).
3. Press any button to stop the tone.

Reminder
After you create a reminder for an appointment, anniversary, or some other event you don’t want to forget, the watch will remind you when that day arrives.

Checking Reminder Notifications
[REM] flashes on the display during a day when there is an anniversary or event that was created with the CASIO WATCHES phone app. Pressing (A) will display the title assigned to the reminder.

Creating a Reminder
Use CASIO WATCHES to create reminders. To use CASIO WATCHES, you first need to
pair your watch with a phone. l Getting Ready If the watch is already paired with a phone, use CASIO WATCHES to create reminders. l Configuring Reminder Settings

After the title is displayed once, the date of the reminder will appear with the dot between the month and day flashing. Pressing (A) while the dot is flashing will display the title again.
Note If you turn on display illumination on a
reminder date, the display light will flash red for a few seconds after illumination automatically turns off.

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Watch Operation Guide 3540

Other Settings
This section explains other watch settings you can configure.
Changing the Date Display Format
1. Enter the Timekeeping Mode. l Navigating Between Modes
2. Hold down (A) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.
Home City

Specifying the Day of the Week Language
You can select any one of six languages for the day of the week display in the Timekeeping Mode. 1. Enter the Timekeeping Mode.
l Navigating Between Modes 2. Hold down (A) for at least two seconds.
Release the button when the name of the currently selected Home City appears on the display.
Home City
3. Press (C) 10 times. This causes the language setting to flash.

Enabling the Button Operation Tone
Use the procedure below to enable or disable the tone that sounds when you press a button. 1. Enter the Timekeeping Mode.
l Navigating Between Modes 2. Hold down (A) for at least two seconds.
Release the button when the name of the currently selected Home City appears on the display.
Home City
3. Press (C) 11 times. This causes [KEY] or [MUTE] to flash on the display.

3. Press (C) nine times. This displays a screen for selecting the date display format.
4. Press (D) to select a date display format. [M.DD]: Month, day [DD.M]: Day, month
5. Press (A) to exit the setting screen. Note While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation.

4. Use (D) to select a language. [ENG]: English [ESP]: Spanish [FRA]: French

5. Press (A) to exit the setting screen.
Note
While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation.

4. Press (D) to select [KEY] or [MUTE]. [KEY]: Operation tone enabled. [MUTE]: Operation tone muted.
5. Press (A) to exit the setting screen. Note
While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation.
Note that alarm and timer tones will still sound even while the operation tone is muted.

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Watch Operation Guide 3540

Configuring Power Saving Function Settings
1. Enter the Timekeeping Mode. l Navigating Between Modes
2. Hold down (A) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.
Home City
3. Press (C) 14 times. This displays [POWER SAVING].
4. Press (D) to toggle between on and off. [On]: Power Saving enabled. [OFF]: Power Saving disabled.
5. Press (A) to exit the setting screen. Note While the setting is being configured, the watch will exit the setting operation automatically after about two or three minutes of non-operation. For details about Power Saving, refer to the information below. l Power Saving Function

Resetting Watch Settings
This section explains how to return the watch settings below to their initial factory defaults. Watch Settings Reminder Stopwatch Timer Alarm 1. Enter the Timekeeping Mode.
l Navigating Between Modes 2. Hold down (A) for at least two seconds.
Release the button when the name of the currently selected Home City appears on the display.
Home City
3. Press (C) twice. This causes the seconds to flash.
Seconds
4. Hold down (B) for at least seven seconds. Release the button when [ALL] stops flashing.
Note While the setting is being configured,
the watch will exit the setting operation automatically after about two or three minutes of non-operation. Resetting the watch will also delete information for pairing the watch with a phone, and unpair them.

Other Information
This section provides non-operational information you also need to know. Refer to this information as required.

City Table

City

Offset

UTC

Coordinated Universal Time 0

LONDON *

London

PARIS *

Paris

+1

ATHENS *

Athens

+2

JEDDAH

Jeddah

+3

TEHRAN

Tehran

+3.5

DUBAI

Dubai

+4

KABUL

Kabul

+4.5

KARACHI

Karachi

+5

DELHI

Delhi

+5.5

KATHMANDU Kathmandu +5.75

DHAKA

Dhaka

+6

YANGON

Yangon

+6.5

BANGKOK

Bangkok

+7

HONG KONG * Hong Kong +8

PYONGYANG ** Pyongyang +8.5

EUCLA

Eucla

+8.75

TOKYO *

Tokyo

+9

ADELAIDE

Adelaide

+9.5

SYDNEY

Sydney

+10

LORD HOWE ISLAND

Lord Howe Island

+10.5

NOUMEA

Noumea

+11

WELLINGTON Wellington

+12

CHATHAM ISLANDS

Chatham Islands

+12.75

NUKU’ALOFA Nuku’alofa

+13

KIRITIMATI

Kiritimati

+14

BAKER ISLAND Baker Island -12

PAGO PAGO Pago Pago -11

HONOLULU Honolulu

-10

MARQUESAS Marquesas

ISLANDS

Islands

-9.5

ANCHORAGE Anchorage

-9

LOS ANGELES * Los Angeles -8

DENVER *

Denver

-7

CHICAGO *

Chicago

-6

NEW YORK * New York

-5

HALIFAX *

Halifax

-4

ST. JOHN’S

St. John’s

-3.5

RIO DE JANEIRO Rio de Janeiro -3

F.

DE

NORONHA

Fernando Noronha

de

-2

PRAIA

Praia

-1

28

Watch Operation Guide 3540

• Cities where time calibration signal reception is possible. ** In May 2018, the offset for PYONGYANG was changed to +9. However, this watch does not reflect that change. Because of this, selecting PYONGYANG will set an offset of +8.5. The information in the above table is current
  as of January 2023. Time zones may change and UTC
  differentials may become different from those shown in the table above. If this happens, connect the watch with a phone to update the watch with the latest time zone information.
  Summer Time Table
  When [AUTO] is selected for a city that observes summer time, switching between standard time and summer time will be performed automatically at the timing shown in the table below.
  Note
  Summer time start and end dates for your current location may be different from those shown below. If this happens, you can have new summer time information for your Home City and World Time City sent to the watch by connecting the watch with a phone. If the watch is not connected with a phone, you can change the summer time setting manually.

City Name

Summer Time Start

Summer Time End

London

01:00, last Sunday in March

02:00, last Sunday in October

Paris

02:00, last Sunday in March

03:00, last Sunday in October

Athens

03:00, last Sunday in March

04:00, last Sunday in October

Tehran

00:00, March 22 or 21

00:00, September 22 or 21

Sydney, Adelaide

02:00, first Sunday in October

03:00, first Sunday in April

Lord Howe Island

02:00, first Sunday in October

02:00, first Sunday in April

02:00, last Wellington Sunday in
September

03:00, first Sunday in April

Chatham Islands

02:45, last Sunday in September

03:45, first Sunday in April

Anchorage

02:00, second Sunday in March

02:00, first Sunday in November

Los Angeles

02:00, second Sunday in March

02:00, first Sunday in November

Denver

02:00, second Sunday in March

02:00, first Sunday in November

Chicago

02:00, second Sunday in March

02:00, first Sunday in November

New York

02:00, second Sunday in March

02:00, first Sunday in November

Halifax

02:00, second Sunday in March

02:00, first Sunday in November

St. John’s

02:00, second Sunday in March

02:00, first Sunday in November

The information in the above table is current as of January 2023.

Specifications
Accuracy at normal temperature : ±15 seconds per month average when time adjustment by time calibration signal reception or by communication with a phone is not possible.
Timekeeping : Hour, minute, second, year, month, day, day of the week a.m./p.m.(P)/24-hour timekeeping Full Auto Calendar (2000 to 2099) Year display on setting screen only.
Signal Receive Functions : Auto receive, manual receive Auto summer time switching Auto transmitter selection (for JJY, MSF/ DCF77) Receivable call signs: JJY (40 kHz/60 kHz), WWVB (60 kHz), MSF (60 kHz), DCF77 (77.5 kHz), BPC (68.5 kHz) OFF: Signal receive disabled
World Time : Current time in 39 cities (39 time zones) and for UTC, auto summer time switching Home City/World Time City swapping
Alarm : Time alarm Alarms: 5 (with one snooze alarm) Setting units: Hours, minutes Beeper: 10 seconds Hourly time signal Beeps every hour on the hour
Stopwatch : Measurement unit: 1/100 seconds (first hour); 1 second (after first hour) Measurement range: 23 hours, 59 minutes, 59 seconds (24 hours) Measurement functions: Elapsed time, split time, two finishes

Supported Phones
For information about phones that can connect with the watch, visit the CASIO website. https://world.casio.com/os_mobile/wat/

29

Watch Operation Guide 3540

Timer :
Measuring unit: 1 second Countdown range: 24 hours Setting unit: 1 second Time up: 10-second beeper
Mobile Link :
Auto Time Adjustment Time setting adjusted automatically at preset time
One-touch Time Correction Manual connection and time adjustment
Phone finder Watch operation sounds the alert sound of the mobile phone
World Time Current time for approximately 300 cities selected for the watch Home Time/World Time swapping Original city function (location and name settings)
Auto Summer Time Switching Automatic switching between standard time and summer time
Timer Settings Alarm Settings Reminder
Reminds you of anniversaries and other important dates. TIME & PLACE Data Communication Specifications Bluetooth® Frequency Band: 2400MHz to 2480MHz Maximum Transmission: 0 dBm (1 mW) Communication range: Up to 2 meters (depends on environment)

Other : LED backlight light (Super Illuminator, afterglow with selectable 2 or 4-second duration), Full Auto light, Power Saving, operation tone enable/disable, selectable date format, selectable day of the week language, auto time adjustment enable/ disable
Power Supply : Solar panel and one rechargeable battery Battery operating time: Approximately 10 months Conditions: Not exposed to light under the conditions below. Auto time adjust by smartphone: 4 times/ day Alarm: Once (10 seconds)/day Illumination: Once (2 seconds)/day Power Saving: 6 hours/day
Specifications are subject to change without notice.
Copyrights and Registered Copyrights
The Bluetooth® word mark and logos are registered trademarks owned by the Bluetooth SIG, Inc. and any use of such marks by CASIO Computer Co., Ltd. is under license.
iPhone and App Store are trademarks of Apple Inc. in the United States and other countries.
iOS is a trademark or registered trademark of Cisco Systems, Inc.
Android and Google PlayTM are trademarks or registered trademarks of Google LLC.
Other company names and product names used herein are trademarks or registered trademarks of their respective companies.

Troubleshooting
Signal Reception (Time Calibration Signal)
Q1 The watch cannot perform a receive operation.
Is the watch’s battery charged?
Signal reception is not possible while battery power is low. Keep the watch exposed to light until it recharges sufficiently. l Charging
Is the watch in the Timekeeping Mode?
Time signal receive is performed only while the watch is in the Timekeeping Mode. Return to the Timekeeping Mode. l Navigating Between Modes
Is your Home City setting correct for your location?
The watch will not indicate the correct time if the Home City setting is wrong. Change your Home City setting so it correctly reflects your location. l Setting a Home City
Is the watch connected with a phone?
Auto receive of signals by the watch is disabled while it is connected with a phone. l Time Adjustment Using a Time Signal
After checking the above, the watch still cannot perform a receive operation.
Time calibration signal reception is not possible under the conditions described below. When watch is at Level 2 power saving Timer countdown operation in progress If successful reception is not possible for some reason, you can adjust the time and day settings manually.

30

Watch Operation Guide 3540

Q2 The signal receive operation always fails.
Is the watch in a location that is appropriate for signal reception?
Check your surroundings and move the watch to a location where signal reception is better. l Appropriate Signal Reception Location
Did you avoid touching the watch while the receive operation was in progress?
Minimize movement of the watch and do not perform any watch operation while a receive operation is in progress.
Is there an alarm configured to sound during the same period that the signal receive operation is performed?
Receive stops if an alarm operation starts while it is being performed. Disable the alarm. l Turning Off an Alarm or the Hourly
Time Signal
Is the signal transmitter in your area transmitting a signal?
The transmitter of the time calibration may not be transmitting a signal. Try again later.
Q3 Signal reception should have been successful, but the watch’s time and/ or day is wrong.
Adjust time and day settings manually. l Using Watch Operations to Adjust the Time
Setting

I can’t pair the watch with a phone.
Q1 I’ve never been able to establish a (pairing) connection between the watch and phone.
Are you using a supported phone model?
Check if the phone model and its operating system are supported by the watch. For information about supported phone models, visit the CASIO Website. https://world.casio.com/os_mobile/wat/
Did you install the CASIO WATCHES phone app on your phone?
The CASIO WATCHES phone app needs to be installed on your phone in order to connect with the watch. l A Install the app on your phone.
Are your phone’s Bluetooth settings configured correctly?
Configure the phone’s Bluetooth settings. For details about setting procedures, see your phone documentation. iPhone Users “Settings” n “Bluetooth” n On “Settings” n “Privacy” n “Bluetooth”
n “CASIO WATCHES” n On Android Users Enable Bluetooth.
Other than the above.
Some phones need to have BT Smart disabled to use CASIO WATCHES. For details about setting procedures, see your phone documentation. On the Home Screen, tap: “Menu” n “Settings” n “Bluetooth” n “Menu” n “BT Smart settings” n “Disable”.

I can’t reconnect the watch and phone.
Q1 The watch will not re-connect with the phone after they are disconnected.
Is the CASIO WATCHES phone app running?
The watch cannot re-connect with your phone unless CASIO WATCHES is running on the phone. On your phone’s Home Screen, tap the “CASIO WATCHES” icon. Next, on the watch, hold down (C) for at least three seconds.
Have you tried turning your phone off and then back on again?
Turn your phone off and then back on, and then tap the “CASIO WATCHES” icon. Next, on the watch, hold down (C) for at least three seconds.

31

Watch Operation Guide 3540

Q2 I can’t connect while my phone is in the Airplane Mode.
Connection with the watch is not possible while the phone’s Airplane Mode is enabled. After disabling the phone’s Airplane Mode, go to the phone’s Home Screen and tap the “CASIO WATCHES” icon. Next, on the watch, hold down (C) for at least three seconds.
Q3 I changed the phone’s Bluetooth from enabled to disabled, and now I can’t connect anymore.
On your phone, re-enable Bluetooth, and then go to the Home Screen and tap the “CASIO WATCHES” icon. Next, on the watch, hold down (C) for at least three seconds.
Q4 I can’t connect after turning off the phone.
Turn your phone off and then back on, and then tap the “CASIO WATCHES” icon. Next, on the watch, hold down (C) for at least three seconds.

Phone-Watch Connection
Q1 I can’t establish a connection between the phone and watch.
Have you tried turning your phone off and then back on again?
Turn your phone off and then back on, and then tap the “CASIO WATCHES” icon. Next, on the watch, hold down (C) for at least three seconds.
Has the watch been re-paired with the phone?
Delete the pairing information from the CASIO WATCHES phone app and your phone (iPhone only), and then re-pair them. l Deleting Pairing Information from the
CASIO WATCHES phone app l C Pair the watch with a phone.
If you are unable to establish a connection…
After deleting pairing information from the watch, re-pair it with your phone. l Deleting Pairing Information from the
Watch l C Pair the watch with a phone.
Changing to a Different Phone Model
Q1 Connecting the current watch to another phone.
Delete the pairing information from your watch and then pair it with the phone you want to connect with. l If you purchase another phone

Auto Time Adjustment by Bluetooth Connection (Time Adjustment)
Q1 When does the watch adjust its time?
The watch will connect with the phone and perform auto time adjustment at around 12:30 a.m., 6:30 a.m., 12:30 p.m. and 6:30 p.m. The connection is automatically terminated after auto time adjustment is complete.
Q2 Auto time adjustment is not performed at a scheduled time.
Is auto time adjustment not being performed according to its normal schedule?
Note that auto time adjustment is not performed for 24 hours after swapping of the Home Time and World Time, or after the time setting is adjusted manually on the watch. Auto time adjustment will resume 24 hours after either of the above operations is performed.
Is a timer countdown operation in progress?
Auto time adjustment will not start at the scheduled times if a timer countdown operation is in progress. Stop the timer countdown operation. l Using the Timer
Is auto time adjustment enabled?
Auto time adjustment will not be performed at the scheduled times unless it is enabled. Enable auto time adjustment. l Using the Watch in a Medical Facility or
Aircraft

32

Watch Operation Guide 3540

Q3 The watch does not connect with a phone and adjust its time when I press (D).
The watch will not adjust its time if you press (D) while a timer countdown operation is in progress. Stop the timer countdown operation and then press (D) again.
Q4 Time is not displayed correctly. If your phone is unable to receive a signal because you are outside its service range or for some other reason, the watch may not be able to display the correct time. If this happens, connect the phone to its network and then adjust the time setting.
Alarm and Hourly Time Signal

Charging
Q1 The watch does not work even though it is exposed to light.
The watch stops operating whenever the battery goes dead. Keep the watch exposed to light until it recharges sufficiently. l Dead Battery
Q2 [R] is flashing on the digital display.
The watch is in the charge recovery mode. Wait until the recovery process is complete (about 15 minutes). The watch will recover more quickly if you place it in a brightly lit location. If an alarm, hourly time signal, illumination
and/or other power-intensive functions are used within a short period of time, the charging capacity of the battery will drop and cause the watch to go into a charge recovery mode. Function availability will be temporarily limited, but functionality will return after the battery recovers. l Dead Battery

Q1 An alarm does not sound.
Is the watch’s battery charged? Keep the watch exposed to light until it recharges sufficiently. l Charging
Other than the above. The alarm’s settings may not be configured. Configure the alarm settings. l Configuring Alarm Settings
Q2 The hourly time signal does not sound.
Is the watch’s battery charged? Keep the watch exposed to light until it recharges sufficiently. l Charging
Other than the above. The hourly time signal may be disabled. Enable the hourly time signal. l Enabling the Hourly Time Signal

Q3 [CHG] is flashing on the display. The charge level of the watch is extremely low. Immediately expose the watch to light to charge it. l Low Battery
Other
Q1 I can’t find the information I need here.
Visit the website below. https://world.casio.com/support/

33

References

• Timepieces (Watches) | CASIO
• Support | CASIO

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