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