Annual Calendar Watches
Patek Philippe invented the annual calendar in 1996. Adjusts the date automatically for 30/31-day months — needs correction only once per year (Feb 28 → Mar 1). The 5326G Travel Time Annual Calendar, 5205R, and 5905R define the modern Patek annual calendar lineup. Rolex's Sky-Dweller is the only other major brand running an annual calendar.