DECLARE SUB clrit ()
DEFINT A-Z               ‘ Default variable type is integer

TYPE MonthType
Number AS INTEGER     ‘ Number of days in the month
MName AS STRING * 9   ‘ Name of the month
END TYPE
DECLARE FUNCTION IsLeapYear% (N%)
DECLARE FUNCTION GetInput% (Prompt$, Row%, LowVal%, HighVal%)

DECLARE SUB PrintCalendar (Year%, Month%)
DECLARE SUB ComputeMonth (Year%, Month%, StartDay%, TotalDays%)
DIM MonthData(1 TO 12) AS MonthType
user$ = COMMAND$
IF user$ <> “SBP” THEN END
COLOR 12, 1: clrit
FOR i = 1 TO 12
READ MonthData(i).MName, MonthData(i).Number
NEXT

‘ Main loop, repeat for as many months as desired:
DO
CALL clrit

‘ Get year and month as input:
LOCATE 3, 3
COLOR 15: PRINT “               C H O O S E    Y O U R    C A L E N D A R”
COLOR 3: Year = GetInput(“     Year (1900 to 2050): “, 12, 1899, 2050)
Month = GetInput(“     Month (1 to 12): “, 13, 1, 12)
PRINT : PRINT
PrintCalendar Year, Month
COLOR 0, 0: LOCATE 1, 1: PRINT STRING$(80, 32);
COLOR 7, 1
LOCATE 21, 53: PRINT “SYSTEM TIME/DATE”
LOCATE 23, 55: PRINT DATE$
COLOR 23, 4: LOCATE 1, 17: PRINT ” Press Any Key “
COLOR 7, 4: LOCATE 1, 34: PRINT ” OR “
LOCATE 1, 40: PRINT ” Shift + Print Screen “: COLOR 7, 1

DO
COUNT = COUNT + 1
SLEEP 1
COLOR 7: LOCATE 22, 56: PRINT TIME$
IF COUNT = 1 THEN GOTO RIGHT
IF COUNT > 1 THEN COUNT = 0
LEFT:
LOCATE 1, 32: K$ = INKEY$
GOTO LFTLOOP
RIGHT:
LOCATE 1, 16: K$ = INKEY$
LFTLOOP:
LOOP WHILE K$ = “”
COLOR 7, 4: LOCATE 1, 17: PRINT ” Press Any Key “
COLOR 20, 1: LOCATE 22, 26
PRINT : PRINT “     New Calendar?”;
COLOR 4: PRINT ” (y or n)   “;
LOCATE , , 1, 0, 13
Resp$ = INPUT$(1)
PRINT Resp$
LOOP WHILE UCASE$(Resp$) = “Y”
CALL clrit
END

‘ Data for the months of a year:
DATA January, 31, February, 28, March, 31
DATA April, 30, May, 31, June, 30, July, 31, August, 31
DATA September, 30, October, 31, November, 30, December, 31

SUB clrit
COLOR 0
FOR i = 1 TO 24
LOCATE i + 1, 1: PRINT STRING$(80, 32)
NEXT i
END SUB

‘
SUB ComputeMonth (Year, Month, StartDay, TotalDays) STATIC
SHARED MonthData() AS MonthType
CONST LEAP = 366 MOD 7
CONST NORMAL = 365 MOD 7
NumDays = 0
FOR i = 1899 TO Year – 1
IF IsLeapYear(i) THEN         ‘ If year is leap, add
NumDays = NumDays + LEAP   ‘ 366 MOD 7.
ELSE                          ‘ If normal year, add
NumDays = NumDays + NORMAL ‘ 365 MOD 7.
END IF
NEXT
FOR i = 1 TO Month – 1
NumDays = NumDays + MonthData(i).Number
NEXT
TotalDays = MonthData(Month).Number
IF IsLeapYear(Year) THEN
IF Month > 2 THEN
NumDays = NumDays + 1
ELSEIF Month = 2 THEN
TotalDays = TotalDays + 1

END IF
END IF

StartDay = NumDays MOD 7
END SUB

‘
‘
FUNCTION GetInput (Prompt$, Row, LowVal, HighVal) STATIC
LOCATE Row, 40, 1, 0, 13
PRINT Prompt$;
Column = POS(0)
DO
LOCATE Row, Column   ‘ Locate cursor at end of prompt
PRINT SPACE$(10)     ‘ Erase anything already there
LOCATE Row, Column   ‘ Relocate cursor at end of prompt
INPUT “”, Value      ‘ Input value with no prompt
LOOP WHILE (Value < LowVal OR Value > HighVal)
GetInput = Value

END FUNCTION

‘
FUNCTION IsLeapYear (N) STATIC
IsLeapYear = (N MOD 4 = 0 AND N MOD 100 <> 0) OR (N MOD 400 = 0)
END FUNCTION

‘
SUB PrintCalendar (Year, Month) STATIC
SHARED MonthData() AS MonthType
ComputeMonth Year, Month, StartDay, TotalDays

Header$ = RTRIM$(MonthData(Month).MName) + “,” + STR$(Year)
LeftMargin = (35 – LEN(Header$)) \ 2
LOCATE 10, 1
PRINT TAB(LeftMargin); Header$
PRINT
PRINT “Su    M   Tu    W   Th    F   Sa”
PRINT
LeftMargin = 5 * StartDay + 1
PRINT TAB(LeftMargin);
FOR i = 1 TO TotalDays
PRINT USING “##   “; i;
IF POS(0) > 35 THEN PRINT

NEXT

END SUB