Breguet Classique in 18-carat gold showing the date, the day and the phases and age of the moon (Ref. 7337BB/Y5/9VU).
The Moon’s phases can be tracked by the moon phase display on watches.
The moon phase display is typically indicated by a semi-circular aperture on the dial with a rotating disc beneath that is usually imprinted with two full moon images. Two half rounded shapes, known tongue-in-cheek as “bosoms”, cover the disc because it allows for a more accurate depiction of the moon phases. As one moon image emerges and disappears, the waxing and waning phases respectively, are more realistically illustrated. A new moon phase is indicated no moon is seen.
Basic moon phase displays have a 59-tooth wheel and this allows the disc to complete its rotation once every 59 days. In other words, each lunation is 29.5 days. However, a lunar cycle is actually 29 days, 12 hours, 44 minutes and 2.8 seconds. The error of 2,642.8 seconds during each lunar cycle will translate into a full day error in around 33 months or about two years and 9 months. This is within an acceptable range.
There are also more accurate moon phase mechanisms in watches with geared transmissions that will be accurate for more than 122 years before a full day error results. These can be found in watches from brands such as Patek Philippe, Blancpain and Piaget.
The Moon’s phases should not be taken for granted as Earth’s natural satellite impacts our daily lives. Tide levels for example, are determined by the Moon’s orbital position because of its gravitational pull. During the new moon and full moon phases, higher tides will be experienced.
High tidal levels are all the more evident during spring tides when the Sun, Moon and Earth are in alignment during a full moon or new moon. Sudden flash floods have occurred during spring tides.
Conversely, lower tide levels are experienced during the quarter moon phases – the half moon / first quarter moon and the last quarter / third quarter moon phases because gravitational forces from the Sun and Moon counteract each other
For some, farming and gardening activities depend on lunar cycles, based on the belief that harvests improve with seeds sown during the new moon and full moon phases.
The Moon will always remain important and culturally significant. The date for the Chinese Lunar New Year for example, always changes because it falls on the second new moon after the winter solstice in December.