Luna Mundi A set of watches consisting of the “Ursa Major” in an 18K white gold case and the “Southern Cross” in an 18K pink gold case. Both watches feature a continuously driven and very precise moon phase indication. Unlike most moon phases in less sophisticated movements which only adjust twice a day the A. Lange approach to advance the moon disc provides a much higher degree of precision and a deviation from the visible lunar orbit of only 1 day in 122.6 years if the watch is kept running continuously. The “Ursa Major” has 398 movement parts and displays the moon phase as seen from the Northern hemisphere; the “Southern Cross” has 402 parts and displays the moon phase as seen from the Southern one. The difference in the movement parts is due to the fact that the moon disc for the Northern hemisphere is rotating clockwise the one for the Southern hemisphere is rotating counterclockwise. The “Ursa Major” is the first wristwatch to realistically display the waxing and waning of the moon as it can be seen from North of the equator.