SUBROUTINE JULIANt(iyear0,iyear,month,iday,time,itimesig,
     *                   xjulian,jsig)

C    COMPUTES JULIAN DAY, INCLUDING TIME, WITH RESPECTS
C    TO MIDNIGHT JANUARY 1 OF THE BASE YEAR

C    ADAPTED FROM ORIGINAL SUBROUTINE CREATED BY LINDA STATHOPOLIS

c*************************************************************
c
c    Passed variables
c
c     iyear0 - base year for calculating julian day
c     iyear - present year
c     month,iday - present month,day
c     time - present time
c     itimesig - number of significant figures in time
c     xjulian - output julian day
c     jsig - output number of significant figures for julian day
c
c************************************************************

      parameter (bmiss=-1E10,zdays=365.)
      dimension yrnorm(13),monthend(12)

c     double precision xjuliand,xtime

      data monthend/31,28,31,30,31,30,31,31,30,31,30,31/
      data yrnorm/0,31,59,90,120,151,181,212,243,273,304,334,365/

      xday=iday
      iadd=0
      xadd=0.
      xjulian0=0.
      xjulian=bmiss
      jsig=0
      iprect=itimesig

c     Calculate days to add between base year and present year

      do 50 i=iyear0,iyear-1
       x1=0.
       if ( (i/4)*4 .eq. i ) x1=1.
       if ( (i/100)*100 .eq. i .and.
     *      (i/400)*400 .ne. i ) x1=0.
       xjulian0=xjulian0+zdays+x1
50    continue

c     Check fo leap year

      if ( (iyear/4)*4 .eq. iyear .and. month .gt. 2 ) xadd=1.
      if ( (iyear/100)*100 .eq. iyear .and.
     *     (iyear/400)*400 .ne. iyear ) xadd=0.
      if ( (iyear/4)*4 .eq. iyear .and. month .eq. 2 ) iadd=1
      if ( (iyear/100)*100 .eq. iyear .and.
     *     (iyear/400)*400 .ne. iyear ) iadd=0.

c     Do not set julian day if the date is suspect

      if ( iyear .le. 0 .or. month .le. 0 .or. iday .le. 0 
     *     .or. month .gt. 12 ) then
       return
      elseif ( iday .gt. monthend(month)+iadd ) then
       return
      endif

c     Calculate time portion

      if ( time .lt. 0. .or. time .gt. 24 ) then
       xtime=0.
       iprect=0
      elseif ( time .eq. 24. ) then
       xadd=xadd+1.
       xtime=0.
       iprect=2
      else
       xtime=time/24.
      endif

c     Calculate julian day

c     xjuliand=xjulian0+yrnorm(month)+
c    * (xday-1.)+xadd
c     xjuliand=xjuliand + xtime
c     xjulian=xjuliand
      xjulian=xjulian0+yrnorm(month)+
     * (xday-1.)+xadd+ xtime

c     Calculate number of sig figs in julian day

      call findsignif(jsig,iprect,xjulian)
      if ( xjulian .eq. 0.00 .and. xtime .eq. 0. .and.
     *    iprect .eq. 1 ) jsig=2

      return
      end