julian date (JD)

julian date (JD)

The interval of time in days (and fraction of a day) since Greenwich noon on Jan. 1, 4713 BC. The JD is always half a day off from Universal Time, because the current definition of JD was introduced when the astronomical day was defined to start at noon (prior to 1925) instead of midnight. Thus, 1995 Oct. 10. 0 UT = JD 2450000. 5.

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Category: General astronomy
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