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The waning moon.

At 14:20:26 UT Friday 18 August 2017
the waning moon’s phase is

13.27% full

Time Zone:   

Some factors that go into this equation:

Universal Time is 14.3572222222222 in decimal hours.
The Julian date is 2457983.63268418.
The sun’s ecliptic longitude is 145.806616098568 degrees.
Its mean anomaly is 224.37763324227 degrees.
The moon’s true longitude is 103.082715755726 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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