A Patek Philippe annual calendar is a self-winding watch that shows the day, date and month and needs a manual correction only once a year, at the end of February, because it already knows which months have 30 or 31 days. Patek introduced the complication in 1996 and patented the mechanism. This guide explains how it works and compares four references people search for most: the 5146, 5205, 5396 and 5235. Bizak & Co. is a sourcing desk, so every watch mentioned here is found to order rather than held in stock.
Last reviewed on October 28, 2026 by Filip Biczak. Specifications come from Patek Philippe's own pages and documents and can change by dial and year, so confirm the exact reference before you buy. Sources: Patek Philippe, ref. 5205R-011, Patek Philippe, ref. 5235/50R-001 and Patek Philippe, 2016 press release on ref. 5396.
What is a Patek Philippe annual calendar?
It is a calendar complication that sits between a simple date watch and a perpetual calendar. The mechanism tracks the different lengths of the months, so the date jumps correctly from the 30th to the 1st and from the 31st to the 1st without help. The one month it cannot handle is February, which has 28 or 29 days, so you advance the date and month by hand when February ends. Patek's own press material describes the correction as taking only seconds, using small correctors in the case band. A perpetual calendar goes one step further and also accounts for leap years, which is why it is the more complicated and more expensive complication. The Patek Philippe annual calendar collection groups the watches we can source with this complication.
How does the annual calendar correction work?
You make one adjustment per year, at the changeover from February to March. On the 5396, the correctors are small pushers in the case band: Patek's documentation lists the date corrector at 4 o'clock, the day at 10 o'clock, the month at 2 o'clock and the moon phase at 8 o'clock. Pressing them brings the display forward to the correct date. Patek's instructions for use for these calibers also advise against changing the calendar during certain evening and night hours, so check the manual for your reference before you correct it.
Which Patek annual calendar references matter most?
Four references account for most of the interest: the 5146, 5205, 5396 and 5235. They share the same calendar logic but differ in layout and character. The 5146 is the older, classic moon-phase layout with a power-reserve indicator. The 5205 is the current mainstream model with a 24-hour subdial. The 5396 is a Calatrava-style round case with a different dial arrangement. The 5235 uses a regulator-style display and is the most unusual of the four. For how Patek builds its numbers, see our guide to Patek Philippe reference numbers.
| Reference | Case | Movement | Layout | Water resistance |
|---|---|---|---|---|
| 5146 | 39 mm | Caliber 315 S IRM QA LU at launch, later 324 S IRM QA LU | Day and month apertures, date, moon phase and power-reserve indicator | |
| 5205 (5205R-011) | 40 mm, 11.36 mm thick | Caliber 26-330 S QA LU 24H, 35 to 45 hours | Day, date and month apertures, moon phase, 24-hour display | 30 m |
| 5396 (5396R) | 38.5 mm, 11.2 mm thick | Caliber 26-330 S QA LU 24H on current pieces (the version presented at Baselworld 2016 uses the 324 S QA LU 24H), 35 to 45 hours | Day and month apertures up top, date at 6, 24-hour subdial with moon phase | 30 m |
| 5235/50R | 40.5 mm, 10 mm thick | Caliber 31-260 REG QA, 38 to 48 hours | Regulator-style: hour and seconds subdials, sweep minutes hand | 30 m |
What makes the 5146 different?
The 5146 is the classic moon-phase annual calendar and sits earlier in the family tree. Sources describe it as the successor to the original 1996 model, and it was produced in several precious-metal variants. Patek launched it in 2005 with a 39 mm case and caliber 315 S IRM QA LU, and later examples use the 324 S IRM QA LU, so confirm the exact variant before you buy. If you want the traditional layout rather than the newer 24-hour dial, this is the reference to ask about, and we can source it to order.
How does the 5205 compare with the 5146?
The 5205 is the current-generation annual calendar and, unlike the classic 5146 layout, carries a 24-hour subdial. The Patek page for the 5205R-011 lists a 40 mm case, 11.36 mm thickness, caliber 26-330 S QA LU 24H and 30 m water resistance. It shows day, date and month in apertures, moon phases and a 24-hour indication. Our 5205R-010 rose gold review covers one dial and metal in detail.
Where does the 5396 fit?
The 5396 is a Calatrava-cased annual calendar that Patek introduced in 2006, so pre-owned examples can predate 2016. At Baselworld 2016, Patek presented a reworked version of the 5396 to mark the complication's 20th anniversary. The press release calls it the 22nd annual calendar model since 1996 and notes it is not a limited edition. Patek's technical data for the 5396R lists a 38.5 mm rose gold case, 46.8 mm lug to lug and 30 m water resistance. Its layout puts the day and month side by side in an upper double aperture, the date at 6 o'clock and a 24-hour subdial with moon phase below. The moon phase needs a one-day adjustment only about once every 122 years, according to Patek.
What is special about the 5235 regulator?
The 5235 swaps the usual central hands for a regulator-style display while keeping the annual calendar. Patek's page for the 5235/50R-001 lists a 40.5 mm rose gold case, 10 mm thickness, self-winding caliber 31-260 REG QA, a 38 to 48 hour power reserve and 30 m water resistance. Hours and seconds each have their own subdial, a sweep hand shows the minutes, and day, date and month appear in apertures. It is the one of the four that looks least like a conventional dress watch.
Which annual calendar should you choose?
Choose by dial layout and case size first, then by metal. For a traditional moon-phase face, look at the 5146. For the current mainstream model, look at the 5205. For a smaller (38.5 mm) Calatrava case, look at the 5396. For something visually distinct, look at the 5235. If you want to see how these sit among the wider range, browse the Patek Philippe complications or the full Patek Philippe collection. Availability for each reference changes, so we confirm the specific watch before you commit to anything.
Quick answers
What is the difference between an annual calendar and a perpetual calendar?
An annual calendar recognizes months of 30 and 31 days and needs one manual correction a year at the end of February. A perpetual calendar also recognizes February and leap years, so it needs no routine correction.
How often do you adjust a Patek annual calendar?
Once a year, when February ends, and again if the watch stops and the calendar falls out of step. The moon phase is far less demanding, with Patek quoting an adjustment of one day only about every 122 years.
Which Patek annual calendar has a regulator display?
The 5235. Its hours and seconds sit in separate subdials, a sweep hand shows the minutes, and the day, date and month appear in apertures.
Is it safe to change the calendar at night?
Not at certain times. Patek's instructions for use for these calibers warn against changing the calendar during some evening and night hours, so follow the manual for your exact reference.
Related reading: Patek Philippe 5205R-010 annual calendar review, Patek Philippe reference numbers explained and Patek Philippe 5924 Calatrava Pilot Travel Time Chronograph.
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