PRO JDCNV,YR,MN,DAY,HR,JULIAN
if n_params(0) lt 4 then begin
    print,string(7B),'CALLING SEQUENCE: JDCNV,YR,MN,DAY,HR,JULIAN
        return
endif
yr = long(yr) & mn = long(mn) &  day = long(day)    ;Make sure integral
L = (mn-14)/12      ;In leap years, -1 for Jan, Feb, else 0
julian = day - 32075l + 1461l*(yr+4800l+L)/4 + $
         367l*(mn - 2-L*12)/12 - 3*((yr+4900l+L)/100)/4
julian = double(julian) + (HR/24.0D) - 0.5D
return
end