10 REM > Days2
   20 REM calculates day of week
   30 ON ERROR REPORT:PRINT " at line ";ERL:END
   40 DIM monnum%(12),day$(6)
   50 FOR m%=1 TO 12:READ monnum%(m%):NEXT
   60 FOR d%=0 TO 6:READ day$(d%):NEXT
   70 REPEAT
   80   INPUT "Please enter the day of the month "date%
   90   INPUT "Now enter month number (1-12) "mon%
  100   INPUT "Now enter the year "year%
  110   IF year%<40 year%+=100
  120   IF year%<140 year%+=1900
  130 IF year%<1900 OR year%>2099 THEN PRINT '"Sorry, this program only works with years 1900 to 2099"':UNTIL FALSE
  140 year%-=1900
  150 leaps%=year% DIV 4
  160 IF (year% MOD 4)=0 AND mon%<3 AND year%>0 THEN leaps%-=1
  170 total%=year%+leaps%+monnum%(mon%)+date%
  180 total%=total% MOD 7
  190 PRINT '"That day was a "day$(total%)
  200 INPUT '"Do you want another go (y/n)",char$
  210 PRINT
  220 UNTIL LEFT$(char$,1)<>"Y" AND LEFT$(char$,1)<>"y"
  230 DATA 0,3,3,6,1,4,6,2,5,0,3,5
  240 DATA Sunday,Monday,Tuesday,Wednesday,Thursday,Friday,Saturday