PATEK PHILIPPE. A PLATINUM AUTOMATIC ANNUAL CALENDAR WRISTWATCH WITH SWEEP CENTRE SECONDS AND 24 HOUR INDICATION

Reference 5035 was the first wristwatch ever to be fitted with a patented annual calendar. This useful complication automatically corrects the date for months with 30 and 31 days while displaying the month and the day of the week - and only requires correction once a year at the end of February. The model was in production from 1996 to 2005.