1000	EXTEND &

1010 !	Counts the number of Friday the 13ths in a particular year &
!	&
!	Creation date:  13-Jul-79  (Friday the 13th) &
!	&
!	Franklin Mitchell &
!	Computer Operations Supervisor &
!	Erskine College &
!	PO Box 86 F &
!	Due West, South Carolina 29639 &

1020	DIM MONTH$(12%), DAYS%(12%) &

1030	DEF FNMOD.7%(X%) = X% - X%/7%*7% &

1040	READ MONTH$(I%) FOR I% = 1% TO 12% &
\	DAYS%(I%) = 31% FOR I% = 1% TO 12% &
\	DAYS%(4%), DAYS%(6%), DAYS%(9%), DAYS%(11%) = 30% &
\	FEB% = 2% &
\	SUNDAY% = 0% &

1050	DATA "Jan", "Feb", "Mar", "Apr", "May", "Jun"
1060	DATA "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" &

1070	PRINT &
\	START.YEAR.DEFAULT% = 1900% + VAL(RIGHT(DATE$(0%),8%)) &
\	PRINT "Start with what year #"; NUM1$(START.YEAR.DEFAULT%); "#"; &
\	INPUT START.YEAR% &
\	START.YEAR% = START.YEAR.DEFAULT% IF START.YEAR% <= 0% &
\	START.YEAR% = START.YEAR% + 1900% IF START.YEAR% < 100% &
\	IF START.YEAR% < 1584% &
	   THEN &
		PRINT &
	\	PRINT "Sorry, I only work for years 1584 and above." &
	\	GOTO 1070
1080	PRINT &
\	END.YEAR.DEFAULT% = START.YEAR% + 10% &
\	PRINT "  End with what year #"; NUM1$(END.YEAR.DEFAULT%); "#"; &
\	INPUT END.YEAR% &
\	END.YEAR% = END.YEAR.DEFAULT% IF END.YEAR% <= 0% &
\	END.YEAR% = END.YEAR% + 1900% IF END.YEAR% < 100% &

1090	PRINT FOR I%=1% TO 3% &
\	PRINT "**** Friday the 13ths ****    BEWARE!" &
\	PRINT &

1100 FOR YEAR% = START.YEAR% TO END.YEAR% &
\	PRINT &
\	YEAR$ = RIGHT(NUM1$(YEAR%),3%) &
\	FRIDAY.13% = 0% &
\	LAST.YEAR% = YEAR% - 1% &
\	FIRST.DAY% = FNMOD.7%(LAST.YEAR% + LAST.YEAR%/4% &
				- LAST.YEAR%/100% + LAST.YEAR%/400% + 1%) &
\	LEAP% = 0% &
\	LEAP% = 1% IF YEAR%/4%=YEAR%/4. &
			AND (YEAR%/100%<>YEAR%/100. OR YEAR%/400%=YEAR%/400.) &
\	DAYS%(FEB%) = 28% + LEAP%
1110  FOR MONTH% = 1% TO 12% &
\	IF FNMOD.7%(FIRST.DAY%) = SUNDAY% &
	   THEN &
		PRINT "13-"; MONTH$(MONTH%); "-"; YEAR$, &
	\	FRIDAY.13% = FRIDAY.13% + 1% &
	! &
	!	If the 1st day of the month is Sunday, the 13th day = Friday &

1120	FIRST.DAY% = FNMOD.7%(DAYS%(MONTH%) + FIRST.DAY%)
1130  NEXT MONTH% &
\	PRINT TAB(44%); FRIDAY.13%; "in "; NUM1$(YEAR%); "."
1140 NEXT YEAR% &

32767	END