Cover IWC Schaffhausen Portugieser Eternal Calendar in platinum with white lacquer dial
IWC Schaffhausen Portugieser Eternal Calendar in platinum with white lacquer dial
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IWC Schaffhausen introduces the eternal calendar Portugieser wristwatch, which doesn’t require any correction until the year 3999
There’s the perpetual calendar, and now there is the eternal calendar. With a perpetual calendar, the watch automatically adjusts for the leap year which happens once every four years until 2100. The eternal calendar takes it up a notch with a 400-year gear that ensures the date remains accurate until the year 3999!
A little explanation: Years in the Gregorian calendar that are divisible by four are leap years, meaning a 29th day must be added at the end of February. There is, however, an additional correction required to keep the calendar in sync with the actual solar year. Only centurial years that can be divided by 400 are leap years, all others are common years. For instance, 2000 and 2400 are leap years, while 2100, 2200, and 2300 are common years.
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Above IWC Schaffhausen Portugieser Eternal Calendar requires no correction until the year 3999
IWC Schaffhausen Portugieser Eternal Calendar requires no correction until the year 3999
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The perpetual calendar is calibrated for a four-year cycle, which means three common years are always followed by a leap year. By design, 2100, 2200, and 2300 will be interpreted as a leap year—which they are not, meaning a manual correction needs to be made on the watch.
However, IWC Schaffhausen resolves this issue with a 400-year gear, which makes one complete revolution every four centuries, containing three indentations to make an automatic adjustment. Called a secular perpetual calendar, the Portugieser Eternal Calendar is mechanically programmed to take these complex nuances into account and calculate the leap years correctly until at least the year 3999.
This remarkable complication, powered by 52640 calibre that also operates a double perpetual moon phase accurate for up to 45 million years, makes its debut in the new Portugieser in 44.4mm platinum case.
Above 52640 calibre incorporates a 400-year gear
52640 calibre incorporates a 400-year gear
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Brian Cheong leads the watch (Tatler GMT) and jewellery content at Tatler Malaysia, combining sharp editorial insight with years of luxury lifestyle experience. A seasoned journalist in luxury watches based in Kuala Lumpur, Brian had previously helmed World of Watches, Men's Folio and Prestige Malaysia.
