To look up the phase of the moon for any date,
just fill out the form below, then hit "Find Phase."

The full moon.

At 01:18:40 UT Thursday 12 December 2019
the moon was



Some factors that go into this equation:

Universal Time is 1.32777777777778 in decimal hours.
The Julian date was 2458830.49961998.
The sun’s ecliptic longitude was 259.741900815676 degrees.
Its mean anomaly was 337.700195184 degrees.
The moon’s mean longitude was 318.351648 degrees.

These calculations incorporate the switch to the English New Style (N.S.)—i.e., Gregorian— calendar after Wednesday, 02 September 1752; the next day became Thursday, 14 September, skipping eleven days. (Please also note that, while fairly accurate, these calculations remain a bit buggy.)

 Send comments to

© 1997–2020 by 3IP.