Annual calendar

An annual calendar is a complication that adjusts automatically for months of thirty and thirty-one days, needing a manual correction only once a year at the end of February.

It sits between a simple date and a perpetual calendar in complexity and cost, and is valued as a practical everyday complication.

As with any calendar watch, check that all indications advance correctly, and ask whether it has been kept running or needs resetting.

Buyers often weigh an annual calendar as a practical middle ground, so describe clearly which indications it shows and whether it has been serviced recently.