The moon phase function is usually placed in a special shape of the semicircle of the window inside, this particular shape includes a semi-circular arc and two small arc. This shape is carefully designed to combine with the moon on the moon disk so that we can tell us exactly the shape of the moon at the beginning or end of a cycle.
The moon phase function is based on the 29.5-day period to show the moon on the moon phase. This moon phase there are usually two moon and the edge of 59 teeth, the moon wheel by the drive wheel after the push every day to move forward a tooth, this time the moon phase of profit and loss changes can be displayed on the dial The. The principle of the moon phase wheel comes from the average of the monthly phase of profit and loss per 29.5 days for a cycle because the exact rotation period of the moon rotation is 28 days 12 hours 44 minutes 2.9 seconds, so every 33 months moon phase display The error will reach 24 hours. The case will generally be set on the moon phase of the adjustment button, moon phase display and timing and calendar and other functions are separate and relatively independent.