	INTEGER*4 FUNCTION JDAY(IYR,IMON,IDAY,IHR,IMIN,ISEC,ICEN)
C** 
C**    @(#)jday.F	1.1    3/10/88
C**
C**
C***********************************************************************
C**
C**                 PLOT+ Scientific Graphics System
C**
C***********************************************************************
C**
C**
*
*
*  This software was developed by the Thermal Modeling and Analysis
*  Project(TMAP) of the National Oceanographic and Atmospheric
*  Administration's (NOAA) Pacific Marine Environmental Lab(PMEL),
*  hereafter referred to as NOAA/PMEL/TMAP.
*
*  Access and use of this software shall impose the following
*  obligations and understandings on the user. The user is granted the
*  right, without any fee or cost, to use, copy, modify, alter, enhance
*  and distribute this software, and any derivative works thereof, and
*  its supporting documentation for any purpose whatsoever, provided
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*  derivative works and supporting documentation.  Further, the user
*  agrees to credit NOAA/PMEL/TMAP in any publications that result from
*  the use of this software or in any product that includes this
*  software. The names TMAP, NOAA and/or PMEL, however, may not be used
*  in any advertising or publicity to endorse or promote any products
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*  is not obligated to provide the user with any support, consulting,
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*
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*
*
*	Mod J Davison 11.22.95 For 4 digit year

*       Year to be calendar year - 1900, eg, 1880 = -20, 2001 = 101
	IYCEN = IYR + (ICEN - 19)*100

	IF(IMON.GT.2)THEN
	   IM=IMON+1
	   IY=IYCEN
	ELSE
	   IM=IMON+13
	   IY=IYCEN-1
	ENDIF
#ifdef unix
	JDAY=(INT(365.25*IY)+INT(30.6001*IM)+IDAY)*1440+
     *	IHR*60+IMIN
#else
	JDAY=(JINT(365.25*IY)+JINT(30.6001*IM)+IDAY)*1440+
     *	IHR*60+IMIN
#endif
	RETURN
	END
