Annual Calendars Are Goldilocks Complications: Not Too Hot, Not Too Cold, Just Right

In October 1582, Pope Gregory XIII introduced what we now call the Gregorian calendar This is the most widely used calendar in the world, so the vast majority of calendar wristwatches display dates according to it. To what extent the calendar function is accurate from month to month greatly depends on the type of watch it is included in Most advance the date at midnight, disregarding the different lengths of the months completely Those fortunate enough to own perpetual calendars don’t have to worry about this at all because their watches will automatically correct the length of each month and even account for leap years.

The downside, however, is that because of this they are highly complex to make – and therefore expensive. Don’t fret, though, because there is a middle ground between the most basic calendar watches and complex perpetual calendars: this is the annual calendar, which automatically adjusts for each month . Source