Setting a Casio watch: time, date and alarm

Setting a Casio digital watch depends on its module, or movement, more than its model name. First, check the module number on the case back and use it to find the official Casio manual. Below are instructions based on Casio’s manuals for setting the time, date and alarm on common models: the Casio A168 and A158, G-Shock DW-5600 and G-Shock GA-2100. At the end, we discuss Bluetooth watches that set their time automatically from a phone.

First: find the module number

The module number is on the case back, usually in the centre or near the edge. It is usually a three- or four-digit number. Enter it into the manual search on Casio’s website to obtain the PDF manual.

Why does this matter? Watches that look the same may contain different modules. For example, the classic G-Shock DW-5600E has module 3229, while the model in our range, G-Shock DW-5600UE-1ER has module 3525. In Casio manuals, the buttons are usually labelled A, B, C and D. A diagram at the start of the manual shows where each button is located.

If you get confused, do not worry. For example, the A168 and A158 manuals say the watch returns to the normal time display automatically if no button is pressed for a few minutes in setting mode.

Casio A168 (module 3298)

These instructions apply, for example, to Casio Vintage A168WG-9EF and A168WEM-2BEF. Use button B to move between modes.

Time and date:

1. Press B until you reach the time-setting mode. The seconds will start flashing.
2. Use button A to move to the next setting. You can change the seconds, hours, minutes, month, date and day of the week.
3. Use button C to change the flashing number. When the seconds are flashing, C resets them to zero.
4. When finished, press B to return to the time display.

In the normal time display, press C to switch between 12- and 24-hour time. To change to daylight saving time, simply adjust the hour in the same setting mode.

Alarm: select alarm mode with B and press A; the hours will flash. Use A to move between hours and minutes, and C to change the number. Press A again. The alarm will now switch on automatically. In alarm mode, use C to switch between alarm on, hourly time signal on, both on or both off. The light comes on when you hold down A.

Casio A158 (module 593)

This applies, for example, to Casio Vintage A158WEM-7EF and Casio A158WETG-9AEF. In the A158 manual, the buttons are labelled A, C and L.

Time and date:

1. From the normal time display, press C three times. The watch enters the time and date setting mode.
2. Use A to change the flashing number. Hold A for more than two seconds to advance the numbers quickly.
3. Use L to move to the next number. The order is seconds, hours, minutes, month, date and day of the week.
4. When finished, press C.

In the normal time display, press A to switch between 12- and 24-hour time.

Alarm: use C to enter alarm mode. Press L and use A to set the hours. Press L again and use A to set the minutes. Press L to finish. In alarm mode, use A to switch between alarm on, hourly time signal on, both on or both off. Press L to silence a sounding alarm.

G-Shock DW-5600E and DW-5600UE (modules 3229 and 3525)

The manuals for these two modules describe the same process for setting the time and alarm. Use C to move between modes.

Time and date:

1. From the normal time display, press A. The seconds will start flashing.
2. Use C to move to the next setting. You can change the seconds, hours, minutes, year, month and day.
3. Use B to increase the flashing number. When the seconds are flashing, B resets them to zero.
4. Press D while a number is flashing to switch between 12- and 24-hour time.
5. When finished, press A. According to the manual, the watch calculates the day of the week automatically from the date.

Alarm: use C to enter alarm mode. Press A until the hours start flashing. Use C to move between settings, B to change the number and A to finish. For a daily alarm, leave the month and day as dashes. In alarm mode, use B to switch between alarm on, hourly time signal on, both on or both off. Press D to turn on the light.

G-Shock GA-2100 (module 5611)

Module 5611 is used, for example, in G-Shock GA-2100GB-1AER and GA-2100K-1AER. On this watch, you first select a home city, and the watch displays that city’s time. Use C to move between modes. Hold C for two seconds to return to the time display.

Home city, time and date:

1. From the normal time display, hold A until the flashing SET disappears and a city code appears.
2. Use D (+) and B (–) to choose a city in the same time zone as Estonia. The city code table is in the manual.
3. Use C to move through the settings: daylight saving time (DST, which must be on during summer time), 12/24-hour format, seconds, hours, minutes, date (year, month, day), button tones and illumination duration.
4. Change the flashing setting using D and B. For seconds, D resets them to zero.
5. When finished, press A.

Alarm: use C to select alarm mode, then D to select one of the five alarms (AL1–AL5). Hold A until SET disappears and the hours flash. Use C to move between hours and minutes, D and B to change them, and A to finish. To turn an alarm or the hourly time signal (SIG) on or off, select it with D and press A. Press B to turn on the light.

If the hands show a different time from the display: hold A for at least five seconds until SUB flashes on the display. Use D and B to set the day-of-the-week hand to SU. Press C: 0:00 will flash on the display. Use D and B to move the hour and minute hands to 12 o’clock, then press A to finish. Check that the hands and display now show the same time.

Bluetooth watches and the CASIO WATCHES app

Bluetooth Casio watches, such as G-Shock GA-B2100C-9AER (module 5689), set their time automatically from a phone. This requires Casio’s CASIO WATCHES app.

1. Download CASIO WATCHES from the App Store or Google Play and turn on Bluetooth on your phone.
2. Keep the phone within one metre of the watch.
3. Open the app, select ‘My Watch’, then select your watch.
4. Hold button C on the watch for at least three seconds until CNCT flashes on the display.
5. Continue by following the app’s instructions.

After pairing, the GA-B2100 connects to the phone four times a day and corrects the time. You can correct the time immediately by pressing D in the time display while the phone is nearby. Edifice Bluetooth models also use the same app, for example Edifice ECB-S10D-2AEF. Some G-Shock, Baby-G, Edifice and Pro Trek models can also be registered in the app, letting you find the watch’s manual without entering its module number.

If you cannot find the manual

If your watch is not covered here, find its module number on the case back and download the manual from Casio’s support page. If that does not help, write to us at info@kaekellad.ee, including the watch model and module number, and we will help. We are an authorised Casio retailer, and all watches come with a 2-year warranty. If you are looking for a new watch, browse Casio watches or read choosing a G-Shock.