To look up the phase of the moon for any (Common Era) date,
just fill out the form below, then hit “Find Phase.”
At 13:30:41 UT Tuesday 21 September 2021
the moon was
is 13.5280555555556 in decimal hours.
The Julian date was 2459479.49660591.
The sun’s ecliptic longitude was 178.782275914361 degrees.
Its mean anomaly was 257.886378293 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.)