Many of the wrist watches on the market have what they call a perpetual calendar.
What is a perpetual calendar?
Quite simply, the ability to keep track of the current month and date, regardless of the actual number of days in any given month, or leap year.
Meaning, come September 30th, the calendar won’t roll over to September 31st (wait, there is no September 31st…), it’ll move directly to October 1st instead.
Every Month used to have 31…
Watches without a perpetual calendar would just display 31 for the date (since the movement wheel just spins to the next number in line, which as you can see in the picture, goes to 31 for every month). To get the correct date, you’d have to adjust the time yourself (roll ahead one day).
While it’s not a big deal, it’s still a pain. Especially if you haven’t worn your watch in 6 months and realize that it’s off by days.
So perpetual calendars fix all that.
They keep you synced and up-to-date.
But even these aren’t totally perfect…
There are 3 main types of perpetual watches in jewelry stores today:
- Annual Calendars
- Perpetual Calendars
- Satellite Calendars
Let’s take a look at them:
Annual calendars keep track of the current year’s months. Meaning, at the end of the year (which is the last day in February, because of leap year), you may have to readjust the date at that time. Just once a year to make sure you’re back on track.
Perpetual calendars are more complex, and use way more tables to keep up with the months, days and years. Most perpetual calendars will actually keep your watch synched until the year 2100 (just a couple of years away, right?)
Satellite calendars are GPS signal syncing. Modern watches like the Seiko Astron GPS Watch will actually sync by satellite, to keep your watch in tune, second by second, minute by minute. It’s out of this world technology that syncs to your watch anywhere on Earth.
So perpetual calendars are what everyone needs…
A date that’s on time!
Now that’s something to LEAP about!