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piscal/dataassim/math/numrec/f77_sources/julday.for
T
2016-02-03 18:52:05 +00:00

21 lines
550 B
Fortran

FUNCTION julday(mm,id,iyyy)
INTEGER julday,id,iyyy,mm,IGREG
PARAMETER (IGREG=15+31*(10+12*1582))
INTEGER ja,jm,jy
jy=iyyy
if (jy.eq.0) pause 'julday: there is no year zero'
if (jy.lt.0) jy=jy+1
if (mm.gt.2) then
jm=mm+1
else
jy=jy-1
jm=mm+13
endif
julday=int(365.25*jy)+int(30.6001*jm)+id+1720995
if (id+31*(mm+12*iyyy).ge.IGREG) then
ja=int(0.01*jy)
julday=julday+2-ja+int(0.25*ja)
endif
return
END