civil_islamic

Description

civil_islamic converts a provided Civil date into an Islamic (Hijri) date. It works for both the Gregorian calendar and the Julian calendar (see also civil_jdn)

Gory details

The function presented here is just one example of an algorithm to convert a Civil date to an Islamic date. It starts by calling civil_jdn, to calculate the Julian day number for the provided civil date. From this Julian day number, the Islamic year, month and day are derived, by calling jdn_islamic.

Note that the Islamic year is approximately 11 days shorter than the Civil year. This means that the Islamic calendar ``runs faster´´ and will eventually overtake the Civil Calendar. From the first day of the fifth month of the year 20874 (20874-05-01) until the thirtieth day of that month (20874-05-30) the Civil and Islamic dates are exactly the same!

Code section

Sub civil_islamic(ByRef iYear As Integer, _
                  ByRef iMonth As Integer, _
                  ByRef iDay As Integer)
    Call jdn_islamic(civil_jdn(iYear, _
                               iMonth, _
                               iDay), _
                     iYear, iMonth, iDay)
End Sub

See also

civil_jdn, jdn_islamic, islamic_civil

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