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Moon Phase Watches

Moon phase watches chart the progression of the moons different phases of new moons, first quarter, full moons and last quarter. The Moon Phase is a frequent addition to Perpetual Calenders but are nonetheless a complication in their own right and can stand alone on a pocket watch or wristwatch dial. Many people derive pleasure from Moon Phase Watches, whether it be from tracking the ever changing moon's appearance to the aesthetics that the display adds to their already beautiful timepiece, and they are certainly popular with the most well known brands, such as Patek Philippe Watches and Breitling Watches.

The moons phases are shown through an aperture that reveals an image though a disc that is located underneath the watch face. In an ordinary moon phase watch the disc has two luna images that cycle through the aperture to indicate the different phases, and is driven by a wheel with 59 teeth. This wheel is advanced by one notch every 24 hours, by the movement of a delicate finger, allowing for the progression of the phase. With this mechanism type, Moon Phase Watches require adjustment every 2 years, 7 months and approximately 20 days. More specialist Moon Phase Watches are driven by a far more complex and precise system, sometimes referred to as astronomical moon phase watches. The disc on which the moons are presented is driven by a wheel with 135 teeth, resulting in greater precision to match the length of the lunar cycle more accurately. This reduces the need to manually alter the watch to just once every 122 years. Some watches also indicate the “Moons age”, which is the number of days since the last new moon.