99.998 PER CENT PRECISION
How much time elapses from new moon to new moon? The accurate calculation of the so-called lunation is one of the most complex issues of general lunar theory. Indeed, it varies and over a decade can exhibit a difference of more than 13 hours. On average, a lunation lasts 29 days, 12 hours, 44 minutes and 3 seconds. Lange’s watchmakers wanted to reproduce this duration as accurately as possible.
The GRAND LANGE 1 MOON PHASE gives the earth’s companion a place at which it garners the most attention: on the main dial, the moon-phase display occupies a particularly large stage with a disc diameter of 14.3 millimetres. The golden moon tracks the orbit of the original with an accuracy of 99.998 per cent. Once correctly set, the display only needs to be corrected by one day after 122.6 years, assuming the watch runs without interruption.