To look up the phase of the moon for any (Common Era) date,
just fill out the form below, then hit “Find Phase.”
At 21:00:00 UT Thursday 12 December 2019
the moon was
is 21.0166666666667 in decimal hours.
The Julian date was 2458830.49521491.
The sun’s ecliptic longitude was 260.575574961006 degrees.
Its mean anomaly was 338.5087910708 degrees.
The moon’s mean longitude on 00 January 1990 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.)