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Diffstat (limited to 'src/slalib/caldj.f')
| -rw-r--r-- | src/slalib/caldj.f | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/slalib/caldj.f b/src/slalib/caldj.f new file mode 100644 index 0000000..c2d9a6d --- /dev/null +++ b/src/slalib/caldj.f @@ -0,0 +1,57 @@ + SUBROUTINE sla_CALDJ (IY, IM, ID, DJM, J) +*+ +* - - - - - - +* C A L D J +* - - - - - - +* +* Gregorian Calendar to Modified Julian Date +* +* (Includes century default feature: use sla_CLDJ for years +* before 100AD.) +* +* Given: +* IY,IM,ID int year, month, day in Gregorian calendar +* +* Returned: +* DJM dp modified Julian Date (JD-2400000.5) for 0 hrs +* J int status: +* 0 = OK +* 1 = bad year (MJD not computed) +* 2 = bad month (MJD not computed) +* 3 = bad day (MJD computed) +* +* Acceptable years are 00-49, interpreted as 2000-2049, +* 50-99, " " 1950-1999, +* 100 upwards, interpreted literally. +* +* Called: sla_CLDJ +* +* P.T.Wallace Starlink November 1985 +* +* Copyright (C) 1995 Rutherford Appleton Laboratory +*- + + IMPLICIT NONE + + INTEGER IY,IM,ID + DOUBLE PRECISION DJM + INTEGER J + + INTEGER NY + + + + +* Default century if appropriate + IF (IY.GE.0.AND.IY.LE.49) THEN + NY=IY+2000 + ELSE IF (IY.GE.50.AND.IY.LE.99) THEN + NY=IY+1900 + ELSE + NY=IY + END IF + +* Modified Julian Date + CALL sla_CLDJ(NY,IM,ID,DJM,J) + + END |