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SUBROUTINE sla_CALYD (IY, IM, ID, NY, ND, J)
*+
* - - - - - -
* C A L Y D
* - - - - - -
*
* Gregorian calendar date to year and day in year (in a Julian
* calendar aligned to the 20th/21st century Gregorian calendar).
*
* (Includes century default feature: use sla_CLYD for years
* before 100AD.)
*
* Given:
* IY,IM,ID int year, month, day in Gregorian calendar
* (year may optionally omit the century)
* Returned:
* NY int year (re-aligned Julian calendar)
* ND int day in year (1 = January 1st)
* J int status:
* 0 = OK
* 1 = bad year (before -4711)
* 2 = bad month
* 3 = bad day (but conversion performed)
*
* Notes:
*
* 1 This routine exists to support the low-precision routines
* sla_EARTH, sla_MOON and sla_ECOR.
*
* 2 Between 1900 March 1 and 2100 February 28 it returns answers
* which are consistent with the ordinary Gregorian calendar.
* Outside this range there will be a discrepancy which increases
* by one day for every non-leap century year.
*
* 3 Years in the range 50-99 are interpreted as 1950-1999, and
* years in the range 00-49 are interpreted as 2000-2049.
*
* Called: sla_CLYD
*
* P.T.Wallace Starlink 23 November 1994
*
* Copyright (C) 1995 Rutherford Appleton Laboratory
*-
IMPLICIT NONE
INTEGER IY,IM,ID,NY,ND,J
INTEGER I
* Default century if appropriate
IF (IY.GE.0.AND.IY.LE.49) THEN
I=IY+2000
ELSE IF (IY.GE.50.AND.IY.LE.99) THEN
I=IY+1900
ELSE
I=IY
END IF
* Perform the conversion
CALL sla_CLYD(I,IM,ID,NY,ND,J)
END
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