FAQ 4.16 How can I find the Julian Day?

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4.16: How can I find the Julian Day?

    (contributed by brian d foy and Dave Cross)

    You can use the "Time::JulianDay" module available on CPAN. Ensure that
    you really want to find a Julian day, though, as many people have
    different ideas about Julian days. See
    http://www.hermetic.ch/cal_stud/jdn.htm for instance.

    You can also try the "DateTime" module, which can convert a date/time to
    a Julian Day.

            $ perl -MDateTime -le'print DateTime->today->jd'

    Or the modified Julian Day

            $ perl -MDateTime -le'print DateTime->today->mjd'

    Or even the day of the year (which is what some people think of as a
    Julian day)

            $ perl -MDateTime -le'print DateTime->today->doy'


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