Posted on junio 17 2025
Most date watches have one rule that isn’t printed anywhere on the watch: don’t change the date late at night.
Why the time of night matters
The date doesn’t flip all at once at midnight. In most movements the mechanism starts engaging a few hours before and finishes a while after. If you quick-set the date while it’s in the middle of that change, you’re pushing against gears that are already moving, and that can damage the date mechanism.
The safe habit: keep the hands well away from midnight, roughly 9 p.m. to 3 a.m., whenever you change the date. Your watch’s manual gives the exact window for its movement.
Setting it safely
- Pull the crown out to the time-setting position and move the hands to around 6 o’clock.
- Push the crown back to the date position, often the first click out, and turn it until you reach the day before today’s date.
- Pull the crown out to the time position again and turn the hands forward past midnight. The date should change to today. Now you know whether it’s morning or evening on the watch.
- Set the correct time and push the crown back in. Screw it down if it’s a screw-down crown.
Watches that show the day as well usually set it by turning the crown the other way in the date position.
Short months
A standard calendar counts to 31 every month, so after a month with 30 days, or February, you’ll need to move the date forward by hand. A perpetual calendar knows the length of each month, leap years included, and won’t need it.
Citizen’s atomic timekeeping models can also set themselves from a radio time signal where one is received.