\START\
\COMMENT=by James Marshall, converts calendar date to Julian Date
\NAME=DATE2JD
\FILE=date2jd.85p
Disp "Date (yyyy.mmdd)"
Input YEAR
(int (100*(YEAR-int (YEAR))+.1))\->\MON
(int (100*(100*(YEAR-int (YEAR))-MON)+.1))\->\DATE
(int (YEAR))\->\YEAR
Disp "UT (hh.mmss)"
Input HOUR
(int (100*(HOUR-int (HOUR))+.1))\->\M
(100*(100*(HOUR-int (HOUR))-M)\->\S
(int (HOUR))\->\H
(H+(M/60)+(S/3600))\->\HOUR
If MON>2
Goto AAA
(YEAR-1)\->\YEAR
(MON+12)\->\MON
Lbl AAA
If YEAR>1582
Goto BBB
If YEAR\<=\1582
Goto CCC
If MON>10
Goto BBB
If MON\<=\10
Goto CCC
If DATE\<=\15
Goto CCC
Lbl BBB
(2-int (YEAR/100)+int (int (YEAR/100)/4))\->\B
Goto DDD
Lbl CCC
0\->\B
Lbl DDD
If YEAR\>=\0
Goto EEE
(int (365.25*YEAR)-.75))\->\C
Goto FFF
Lbl EEE
(int (365.25*YEAR))\->\C
Lbl FFF
(int (30.6001*(MON+1)))\->\D
(B+C+D+DATE+1720994.5+(HOUR/24))\->\JD
Disp "Julian Date:"
Disp JD
\STOP\

    Source: geocities.com/dronak/progs

               ( geocities.com/dronak)