Annual Calendar
An annual calendar provides an indication that takes automatically into account months with less than 31 days, but not leap years. As a result, it must be adjusted every year. There are exceptions between annual calendars but a general rule is a calendar that indicates the different length of each month automatically jumping to the 1st after the 30th or 31st of the previous month.
Blancpain Quantième Annuel GMT
Laurent Ferrier annual calendar
Patek Philippe annual calendar (Image courtesy of Christies auction house