10 CLS
20 PRINT "DAYS BETWEEN TWO DATES" 
30 PRINT 
40 PRINT "FIRST DATE"; 
50 INPUT M1,D1,Y1 
60 PRINT "SECOND DATE"; 
70 INPUT M2,D2,Y2 
80 M=M1 
90 D=D1 
100 Y=Y1 
110 GOSUB 240  
120 N=A 
130 M=M2 
140 D=D2 
150 Y=Y2
160 GOSUB 240  
170 N=A-N
180 PRINT "DIFFERENCE =";N;"DAYS" 
190 PRINT 
200 PRINT "MORE DATA? (1=YES, 0=NO)"; 
210 INPUT X 
220 IF X=1 THEN 30   
230 GOTO 490  
240 ON M GOTO 270,290,270,350,270,350,270,270,350,270,350,270  
250 PRINT "UNREAL DATE" 
260 RETURN 
270 IF D>31 THEN 250  
280 GOTO 360  
290 IF Y/4<>INT(Y/4) THEN 320  
300 IF Y/400=INT(Y/400) THEN 330  
310 IF Y/100<>INT(Y/100) THEN 330  
320 IF D>28 THEN 250  
330 IF D>29 THEN 250  
340 GOTO 360  
350 IF D>30 THEN 250  
360 DATA 0,31,59,90,120,151,181,212,243,273,304,334
370 RESTORE
380 FOR H=1 TO M
390 READ A 
400 NEXT H
410 A=A+Y*365+INT(Y/4)+D+1-INT(Y/100)+INT(Y/400)
420 IF INT(Y/4)<>Y/4 THEN 480  
430 GOTO 480  
440 IF Y/400=INT(Y/400) THEN 460  
450 IF Y/100=INT(Y/100) THEN 480  
460 IF M>2 THEN 480  
470 A=A-1 
480 RETURN
490 END