Definitions for "Julian date"
Keywords:  noon, january, jan, yyddd, scaliger
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The sequential day count reckoned consecutively beginning January 1, 4713 B.C.
The basis of time for astrodynamics. The number of days since 12:00 on 1 January 4713 B.C. The Julian Day for 1 January 2000 at noon is 2,451,545.0.