Date night: get yourself a mechanical watch that tells you the time *and* date

The most basic function on a wristwatch, beyond the three hands that tell the time, is the date. At its most simple, it is a little wheel with 31 numbers on it that makes one jump every 24 hours. This is all fine, except of course for the fact that not all months have 31 days, so you often find yourself having to change it manually.

An annual calendar displays the month, as well as the date, and the month wheel has five extra fingers, one for each month with fewer than 31 days, allowing the mechanism to skip past number 31 and go straight to the first day of the next month. An annual calendar runs accurately for the whole year, but will need adjusting at the end of February.

If changing your watch once a year is still too much of a faff, you could be a candidate for one of watchmaking’s fanciest functions: the complete, or perpetual calendar. With a load more little toothed wheels, it manages to adjust not only for 30 day months, but for February and leap years as well. It will not need adjusting until the year 2100, when the leap year will be skipped as part of our bid to remain aligned with the universe.

The only catch is it needs power. So if you don’t wind it manually, the watch will run out and you will need to adjust it anyway. A perpetual calendar is very clever – so long as the owner is organised enough to keep it wound up.

Pro tip: start yesterday 

When wearing a watch for the first time, or reviving a dormant mechanical watch, set it to yesterday before starting to adjust the time. Then move the time hands forward until the date moves forward to today. That way you know you’ve got your AM and PM right and the date will change as required in the middle of the night.