#Date Program
#autonumber
new
dim sizeofmonth(11)
dim juliandays(11)

s($5)="Sunday"
s($6)="Monday"
s($7)="Tuesday"
s($8)="Wednesday"
s($9)="Thursday"
s($10)="Friday"
s($11)="Saturday"

sizeofmonth(0)=31
sizeofmonth(1)=28
sizeofmonth(2)=31
sizeofmonth(3)=30
sizeofmonth(4)=31
sizeofmonth(5)=30
sizeofmonth(6)=31
sizeofmonth(7)=31
sizeofmonth(8)=30
sizeofmonth(9)=31
sizeofmonth(10)=30
sizeofmonth(11)=30

juliandays(0)=0
juliandays(0)=31
juliandays(0)=59
juliandays(0)=90
juliandays(0)=120
juliandays(0)=151
juliandays(0)=181
juliandays(0)=212
juliandays(0)=243
juliandays(0)=273
juliandays(0)=304
juliandays(0)=334

40 daynumber = 0

41 input "Enter the month:",MONTH
if MONTH > 12 then goto 41
if month < 1 then goto 41

50 input "Enter the day of month:", DAYOFMONTH
if DAYOFMONTH < 1 then goto 50
MONTH = MONTH - 1
if DAYOFMONTH > sizeofmonth(MONTH) then goto 50

60 input "Enter the year:', YEAR
if YEAR > 1999 then goto 60
if YEAR < 1900 then goto 60

gosub 80

MONTH = MONTH + 1
date$=str$(MONTH) + "-" + str$(DAYOFMONTH) + "-" + str$(YEAR)
dprint date$, "is on a ", s$(daynumber+5)

dprint "The Julian date is ", j, "/", YEAR

input "Enter another date?", s$(4)

if s$(4) = "N" or s$(4) = "n" then end
goto 40

80 j= juliandays(MONTH) + DAYOFMONTH

y=YEAR = 1900

x =365.25 * y + j

rem (y= last 2 digits of year, j = julian day)

xint = int(x)
xdec = x - xint

if xdec = 0 then xint = xint+1: if MONTH > 2 then j = j+1

xint = int(xint/7)
daynumber = x - (xint*7)
return

run