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Bug #6042

DateTime::jd off by 12 hours(?)

Added by Steeljack (Dan Martinez) over 7 years ago. Updated over 7 years ago.

Status:
Rejected
Priority:
Normal
Assignee:
-
Target version:
-
ruby -v:
1.9.2-p290
Backport:
[ruby-core:42707]

Description

I am deeply reluctant to file a bug against something so fundamental as DateTime, and wonder whether I might have missed something, but:

When passed an integral value, DateTime::jd returns a DateTime object whose time is set to midnight GMT:

puts DateTime.jd 2455972
2012-02-14T00:00:00+00:00

The WikiPedia entry for "Julian Day" reads, in part: "Julian day is used in the Julian date (JD) system of time measurement for scientific use by the astronomy community, presenting the interval of time in days and fractions of a day since January 1, 4713 BC Greenwich noon."

It therefore seems to me that a whole number of days since that time would itself necessarily fall on Greenwich noon.

Please feel free to tell me that I'm missing something blindingly obvious.

History

Updated by naruse (Yui NARUSE) over 7 years ago

  • Status changed from Open to Rejected

As rdoc of DateTime.jd says, its argument is Chronological Julian Day number.

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