Perpetual Calendar

One of the most sophisticated complications in watchmaking the perpetual calendar indicates the month and the date in addition to the hours and minutes.

Referred to as perpetual because the calendar requires no adjustment apart for turn of the century years, therefore a contemporary perpetual calendar will not need adjusting until 2100.

It automatically adjusts for leap years and deals with irregular months and moon phases and its mechanism will switch from February 28th to the 1st of March without requiring manual correction.