If there's one watch that needs no introduction, it's the Casio F91W-1. Since 1989 it's been a hugely popular budget digital watch for just about everyone: simple, reliable, and instantly recognisable. With only three buttons and a straightforward digital display, setting the time takes less than a minute once you know the sequence. Here's how it's done.

Know Your Buttons

The F91W-1 keeps things minimal with just three buttons:

• Top left — Light (illuminates the display, also advances through settings)
• Bottom left — Mode (cycles between Timekeeping, Alarm, Stopwatch, and enters the setting screen)
• Bottom right — Adjust (changes the flashing value)

Step by Step: Setting the Time and Date

1. Get to Timekeeping Mode Press the bottom left button (Mode) repeatedly until you're back at the normal time display, showing the time, date and day of the week.

2. Enter setting mode From Timekeeping Mode, press the bottom left button three times in a row. The seconds digits will start flashing: this means you're now in the time setting screen.

3. Adjust the seconds While the seconds are flashing, press the bottom right button (Adjust) to reset them to zero. If the seconds are between 0 and 29 when you press it, only the seconds reset. If they're between 30 and 59, the seconds reset and the minute advances by one, which is handy for syncing to the exact minute.

4. Step through each field Press the top left button (Light) once to move to the next flashing field. The sequence runs:

Seconds, then Hour, then Minute, then Month, then Date, then Day (of the week)

At each field, press the bottom right button (Adjust) to change the value. Press and hold it down for a couple of seconds to advance quickly through numbers, which is much faster than pressing one at a time.

5. Exit setting mode Once everything is correct, press the bottom left button (Mode) to return to normal Timekeeping Mode.

 

A Few Handy Tips

• No year setting. The F91W-1 runs on a pre programmed annual calendar (it even accounts for February's 28 days), so there's no year field to set, just month, date and day of the week.
• 12 hour vs 24 hour format. From the normal Timekeeping display, press the top left button once to toggle between 12 hour and 24 hour ("24H" will appear) formats.
• Automatic timeout. If you leave a field flashing without pressing a button for around 30 to 45 seconds, the watch will automatically exit setting mode and return to normal time, so if it stops responding partway through, just start again from step 2.
• That "CASIo" screen isn't a fault. Holding the bottom right button for a few seconds in Timekeeping Mode brings up a hidden counterfeit check display, a fun party trick that also confirms you've got a genuine module.
• Mind the water resistance. The F91W-1 is rated for light splash resistance only. It's fine for washing your hands or getting caught in the rain, but it's not designed for swimming or showering.

Still not working?

If your F91W-1 isn't responding as expected, make sure you're starting from the normal Timekeeping display before pressing Mode three times. If the watch is sitting in Alarm or Stopwatch mode, the setting sequence won't trigger correctly.

Need a replacement battery, strap or genuine Casio parts for your F91W-1? Get in touch with the team at Watch Supply. We're always happy to help keep your timepiece ticking.