Don’t miss this handy freebie: a perpetual birthday calendar that’s perfect for keeping track of birthdays and other spe ...

Perpetual calendars rely on cycles that repeat. Native Americans used winter counts to convey and hold information about important events of the year with images.

It will take 122 years for it to show a one-day discrepancy with the real moon. Then it will need to be adjusted. Chopard says it is one of the few automatic perpetual calendars to feature a micro ...