The Perpetual Calendar 5940 is a wristwatch by Patek Philippe.

The model was introduced in 2012 at BaselWorld as the successor to the Ref. 5040 and 5041. It features a perpetual calendar in a distinctive cushion-shaped case reminiscent of the Art Deco aesthetic of the 1920s.

The perpetual calendar displays the day of the week, date, month, and leap year cycle and, due to the rules of the Gregorian calendar, will not require manual correction until the year 2100.

Note the elegant serif fonts (numbers and numerals), which lend the watch a stylish ambience.