Definitions for "Annual calendar"
A watch displaying the day, date, month, and 24 hours that adjusts automatically for short and long months. An annual calendar requires only a single manual correction per year from the end of February to the 1st of March.
A watch showing the calendar without correction for a year, 1 March to 28 February.
A watch showing the day, date month and 24 hours, adjusting automatically for short and long months. The calendar needs setting only once a year - at the end of February to the 1st of March.