Patek Philippe’s 5978P joins a chronograph to an instant calendar

Patek Philippe used the Milan edition of its Watch Art Grand Exhibition, open since October 2, 2026, to show a set of seven limited editions. The centerpiece is the reference 5978P-010.

Patek says it is the first time it has paired its hand-wound chronograph and an instantaneous perpetual calendar. “Instantaneous” means the date, day and month all change at once at midnight. On most calendars they turn slowly over a few hours.

The movement

The new caliber is called CH 29-535 PS QI. It has 500 parts and 42 jewels. It beats at 4 Hz, which is 28,800 vibrations per hour. The power reserve is 55 to 65 hours.

Hand-wound means there is no rotor. You wind it by turning the crown. That keeps the back of the movement open to view.

A perpetual calendar knows how many days each month has, including leap years. Set correctly, it should not need a manual date change until the year 2100, when the leap year rule skips a year.

The case and dial

The case is platinum, 42 mm wide and 14.24 mm thick. A small diamond is set in the case at 6 o’clock. The dial is a navy blue sunburst. As a nod to the host city, the calendar names are in Italian.

Numbers and price

Patek will make 120 pieces. Patek lists the price at $337,585.

The 5978P is one of seven Milan limited editions. Patek also showed a six-model Gondolo “Ladies First” line of quartz watches.

Also new in October

Several other notable watches came out this month. Prices are as listed by the brands or reported by Haute Time.

• Grand Seiko SLGH033: Grand Seiko’s Japanese boutique lists an October 9 release. 40 mm case in Ever-Brilliant Steel, 11.7 mm thick, 9SA5 movement at 36,000 vibrations per hour, about 80 hours of reserve. USD 10,200 on Grand Seiko’s US site.
• Hublot Classic Fusion Tributo: $30,900.
• Ressence TYPE 10 DN: 100 pieces, CHF 45,000 before taxes.
• Hermès H08: $8,600.
• URWERK UR-300 Time Quantum: CHF 168,000 before taxes, in two editions of 25 pieces.

What to watch for

If a 5978P comes up at auction, we will report the result. For how auction prices are built, see our guide to how watch auction prices work.

Top photo: Rama via Wikimedia Commons, CC BY-SA 2.0 FR. Resized.