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The waning moon.

At 22:26:16 UT Thursday 12 December 2019
the moon’s phase was

WANING GIBBOUS (99.43% full)


Some factors that go into this equation:

Universal Time is 22.4544444444444 in decimal hours.
The Julian date was 2458830.49426975.
The sun’s ecliptic longitude was 260.636459409907 degrees.
Its mean anomaly was 338.5678386486 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.)

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