Kollektion: Perpetual Calendar Watches

Perpetual calendar watches

A perpetual calendar knows how many days each month has and when February has 29, so you never move the date on by hand at the end of a short month. Every watch here is a Citizen, nearly all Eco-Drive, and many also set themselves from atomic time signals, so the time, date and calendar all look after themselves.

How far ahead it runs

Each Citizen calibre lists how far its calendar goes. The E660 in the Perpetual Chrono A-T and Promaster Sky, and the H874 in the Tsuki-yomi A-T, run until 28 February 2100. The U680 in the Skyhawk A-T runs until 31 December 2099. Either way, the date won’t need correcting for the rest of this century.

Compared with an ordinary date

An ordinary date counts to 31 every month. Citizen’s Calendrier, for example, shows the month, day, date and moon phase, but its date follows a 31-day cycle, so after a 30-day month or February you advance it with the crown. A perpetual calendar does that for you. Our guide to setting the date on your watch shows how an ordinary date is adjusted.

The models

• Perpetual Chrono A-T: 42 to 43 mm, analog, with a chronograph and world time, set by atomic time signals. The CB5919-00X pairs a green dial with a rose gold-tone case on leather. The PCAT Sport and Promaster Sky use the same E660 calibre in sportier cases.
• Promaster Skyhawk A-T: 45 to 46 mm, with digital displays beside the hands, UTC, dual time, alarms and a chronograph to a hundredth of a second, all set by radio. See all of Citizen’s atomic timekeeping watches.
• World Chronograph A-T, Geo Trekker and Tsuki-yomi A-T: world time with a perpetual calendar and atomic timekeeping; the Tsuki-yomi adds a moon phase.
• Without radio: the Promaster Sky U830 and Promaster Land U822 keep a perpetual calendar on their own, along with a chronograph and an alarm. The Promaster Sky U830 JV2000-51L is 43 mm on a steel bracelet. Citizen’s Star Wars ana-digi quartz watches also keep a perpetual calendar on their digital display, in a 33.5 mm rectangular case.

Keeping it right

A perpetual calendar stays right only while the watch keeps running, so the one thing to watch is charge. With Eco-Drive that means light: if the second hand starts jumping every two seconds, give the watch some daylight. The A-T models also pick up the correct time and date by themselves once they’ve recharged after stopping. Our guide to how Eco-Drive works covers charging.

Questions

Does it ever need setting? Once, when you set the year, month and date. After that the calendar runs on its own, and on the A-T models the radio signal keeps it right.

Which is the slimmest? The Star Wars ana-digi models at 9.77 mm, then the Tsuki-yomi A-T at 10.87 mm.

Are any on leather or rubber? Most are on steel or titanium bracelets. For leather, look at the Perpetual Chrono A-T CB5919-00X, the Skyhawk A-T JY8149-05E and the World Chronograph A-T AT8020-03L; for rubber, the PCAT Sport, the Promaster Sky CB5006-02L and the Promaster Land U822 JV1007-07E.