Casio module 3551

1. In the Timekeeping Mode, press D until the Home City Time (T-1) shows.
2. Hold A until the seconds flash.
3. Press C to move through the settings: seconds, DST, city code, hour, minute, 12/24-hour format, year, month, day, light duration.
4. On the seconds, press D to reset them to 00.
5. On the hour, minute, year, month or day, press D to go up and B to go down; on the 12/24-hour format, press D to switch.
6. Press A to leave the setting screen.

From Casio's guide, page EN-12

1. In the Timekeeping Mode, press D until the Home City Time (T-1) shows.
2. Hold A until the seconds flash.
3. Press C once to show the DST setting.
4. Press D to switch between On (summer time) and OFF (standard time).
5. Press A to leave. The DST indicator shows while summer time is on.

From Casio's guide, page EN-16

1. In the Timekeeping Mode, press D until the Home City Time (T-1) shows.
2. Hold A until the seconds flash.
3. Press C twice to reach the city code.
4. Press D (east) or B (west) to pick the city.
5. Press A to leave the setting screen.

From Casio's guide, page EN-12

1. Press C until the Alarm Mode shows.
2. Press D to pick one of the five alarms.
3. Hold A until the hour flashes; this turns on a one-time alarm.
4. Press C to move through hour, minute and the one-time/daily choice.
5. Use D (+) and B (-) for the time; on the last setting press D to choose 1-On (one-time) or On (daily).
6. Press A to leave the setting screen.

From Casio's guide, page EN-24

1. Press B in any mode to light the display (not while a setting screen is shown).
2. To change the duration, open the time setting screen, press C until the light duration flashes, and press D to switch between 1.5 seconds (1) and 3 seconds (3).

From Casio's guide, page EN-19

1. Hold C in any mode (not on a setting screen) to switch the button tone on or off.
2. The mute indicator shows while the tone is off.

From Casio's guide, page EN-37

1. Press C until the Stopwatch Mode shows.
2. Press D to start, D to stop, and D again to carry on.
3. While it runs, press A for a split time (SPL shows); press A again to release it.
4. When it is stopped, press A to clear it.

From Casio's guide, page EN-34

1. Press C until the Timer Mode shows.
2. Hold A until the start time flashes.
3. Press C to move through hours, minutes and seconds, and use D (+) and B (-) to set each.
4. Press A to leave the setting screen.
5. Press D to start, pause and resume the countdown.
6. To reset it to the start time, pause it and press A.

From Casio's guide, page EN-31