The reference that brought an annual calendar to the Nautilus. The mechanism is Patek Philippe's own aperture-style annual calendar, patented in 1996 with the reference 5035: it distinguishes thirty- and thirty-one-day months on its own and needs one correction a year, at the end of February. The /1A suffix denotes the version on a matching steel bracelet.
Reference record
Production
2010–present
Model
Nautilus Annual Calendar
Case material
Stainless Steel
Case size
40.5mm
Movement
Automatic
Calibre
Cal. 324 S QA LU 24H/303
Dial colours
Grey, Blue
Market value band
$75k – $110k
Notable
—Patek Philippe invented and patented the aperture annual calendar in 1996, first fitted to the reference 5035.
—Day and month appear in apertures below twelve o'clock, with a combined date and moonphase subdial at six o'clock and a 24-hour indication.
What the specification implies
—Two movement generations exist across this reference's production run, so the calibre visible through the sapphire caseback depends on the year of manufacture.
—The /1A designation refers to the integrated steel bracelet. Examples designated 5726A were delivered on a strap.
Common questions
When was the Patek Philippe 5726/1A produced?
The 5726/1A has been in production since 2010.
What movement does the Patek Philippe 5726/1A use?
The Patek Philippe 5726/1A runs the Cal. 324 S QA LU 24H/303, an automatic movement.
How do I check a Patek Philippe 5726/1A with Watch Safe?
Look up the watch's serial number in the Watch Safe registry to see whether a record exists or a theft flag is attached. A registry search identifies records for a specific serial; it does not authenticate the watch. Authentication is performed in person by an independent expert authenticator, and Watch Safe records and publishes the result.