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The waning moon.

At 09:48:42 UT Monday 11 December 2017
the waning moon’s phase is

38.82% full

Time Zone:   

Some factors that go into this equation:

Universal Time is 9.82833333333334 in decimal hours.
The Julian date is 2458098.88818302.
The sun’s ecliptic longitude is 259.577871668595 degrees.
Its mean anomaly is 337.54108392 degrees.
The moon’s true longitude is 1622.50041451346 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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