The Jaeger-LeCoultre Duometre Chronograph Moon is the brand’s new high-end timepiece that combines a chronograph with a moon phase
The moon phase or lunar phase is the shape of the sunlit portion of the Moon when you look at it from Earth. These phases change cyclically as the Moon orbits the Earth, according to the changing positions of the Moon and Sun relative to the Earth.
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The Moon’s rotation is tidally locked by the Earth’s gravity, therefore the same lunar surface always faces Earth. This face is variously sunlit depending on the position of the Moon in its orbit. There are four principal lunar phases: new moon (0% sunlit), first quarter, full moon (100% sunlit), and third quarter (also known as last quarter).
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Timing of the Moon’s phases shifts
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The average calendar month, which is 1⁄12 of a tropical year, is about 30.44 days, while the Moon’s phase (synodic) cycle repeats on average every 29.53 days. Therefore, the timing of the Moon’s phases shifts by an average of almost one day for each successive month. (Lunar year=354 days.)
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The approximate moon phase can be calculated for any date by calculating the number of days since a known new moon (such as January 1, 1900 or August 11, 1999) and reducing this modulo 29.530588853 (the length of a synodic month). Can you imagine how watch makers manage to create a complication like this?
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Watches with a moon phase
The A. Lange & Sohne Datograph Perpetual Tourbillon Honeygold Lumen is a limited edition to mark 25 years of the Datograph
The IWC Portugieser Eternal Calendar is doing things beyond imagination with a 400-year gear and one moon phase deviation in 45-million years
The Laurent Ferrier Classic Moon in Blue or Silver is the first moon phase complication of the Swiss brand, and an expansion of the Classic collection
Just when “the world” thought the Moonswatch run was over there is the Omega x Swatch Bioceramic Moonswatch Moonphase – New Moon
The Parmigiani Fleurier Tonda PF Hijri Calendar is the horological expression of the Islamic or Muslim calendar, now available in stainless steel
The F.P. Journe Divine Calibre 1300.3 Boutique Edition is part of FPJ’s collection that is only available at their boutiques
The Raymond Weil Millesime Automatic Moon Phase 39.5 mm is another new “neo-vintage” model by the independent Swiss watchmaker
To welcome this leap year, Blancpain unveils the Blancpain Villeret Quantième Perpétuel Green, a reference to the forest of Le Brassus
The Omega x Swatch Bioceramic Moonswatch Mission to the Moonphase adds a new chapter to the collab with Omega