Difference in minutes

[Jaze]

Here's a function to take two strings of formatted time and return the difference in minutes. The string has to have the format "H:MM ?M M/D/YYYY" Basically when you hit F5 in the windows notepad you get a time stamp with the required format. Hours, day and month can be one or two digits. Spaces are required and it has to be AM or PM, not 24-hour time.

Code: QB64: [Select]

1. FUNCTION GetDifference (earlierTime$, moreRecentTime$) 'returns minutes
2.     colonPosition1 = INSTR(earlierTime$, ":")
3.     colonPosition2 = INSTR(moreRecentTime$, ":")
4.     hours1 = VAL(LEFT$(earlierTime$, colonPosition1 - 1))
5.     hours2 = VAL(LEFT$(moreRecentTime$, colonPosition2 - 1))
6.     minutes1 = VAL(MID$(earlierTime$, colonPosition1 + 1, 2))
7.     minutes2 = VAL(MID$(moreRecentTime$, colonPosition2 + 1, 2))
8.     IF MID$(earlierTime$, colonPosition1 + 4, 1) = "P" THEN hours1 = hours1 + 12
9.     IF MID$(earlierTime$, colonPosition2 + 4, 1) = "P" THEN hours2 = hours2 + 12
10.     month1 = VAL(LTRIM$(MID$(earlierTime$, INSTR(earlierTime$, "/") - 2, 2)))
11.     month2 = VAL(LTRIM$(MID$(moreRecentTime$, INSTR(moreRecentTime$, "/") - 2, 2)))
12.     rightCut1$ = MID$(earlierTime$, INSTR(earlierTime$, "/") + 1, LEN(earlierTime$))
13.     rightcut2$ = MID$(moreRecentTime$, INSTR(moreRecentTime$, "/") + 1, LEN(moreRecentTime$))
14.     day1 = VAL(LEFT$(rightCut1$, INSTR(rightCut1$, "/") - 1))
15.     day2 = VAL(LEFT$(rightcut2$, INSTR(rightcut2$, "/") - 1))
16.     year1 = VAL(MID$(rightCut1$, INSTR(rightCut1$, "/") + 1, 4))
17.     year2 = VAL(MID$(rightcut2$, INSTR(rightcut2$, "/") + 1, 4))
18.     IF hours1 = 24 THEN hours1 = 0
19.     IF hours2 = 24 THEN hours2 = 0
20.     IF month1 <> month2 THEN
21.         SELECT CASE month1
22.             CASE 9, 4, 6, 11
23.                 daysInMonth1 = 20
24.             CASE 1, 3, 5, 7, 8, 10, 12
25.                 daysInMonth1 = 31
26.             CASE 2
27.                 IF year1 MOD 4 = 0 THEN
28.                     daysInMonth1 = 29
29.                 ELSE
30.                     daysInMonth1 = 28
31.                 END IF
32.         END SELECT
33.     END IF
34.     minutesDifferent = 0
35.     currentMinute = minutes1
36.     currentHour = hours1
37.     currentDay = day1
38.     currentMonth = month1
39.     currentYear = year1
40.     DO
41.         minutesDifferent = minutesDifferent + 1
42.         currentMinute = currentMinute + 1
43.         IF currentMinute = 60 THEN
44.             currentMinute = 0
45.             currentHour = currentHour + 1
46.             IF currentHour = 24 THEN
47.                 currentHour = 0
48.                 currentDay = currentDay + 1
49.                 IF currentDay >= 28 THEN
50.                     SELECT CASE currentMonth
51.                         CASE 9, 4, 6, 11
52.                             IF currentDay = 31 THEN
53.                                 currentMonth = currentMonth + 1
54.                                 currentDay = 1
55.                                 IF currentMonth = 13 THEN
56.                                     currentYear = currentYear + 1
57.                                     currentMonth = 1
58.                                 END IF
59.                             END IF
60.                         CASE 1, 3, 5, 7, 8, 10, 12
61.                             IF currentDay = 32 THEN
62.                                 currentMonth = currentMonth + 1
63.                                 currentDay = 1
64.                                 IF currentMonth = 13 THEN
65.                                     currentYear = currentYear + 1
66.                                     currentMonth = 1
67.                                 END IF
68.                             END IF
69.                         CASE 2
70.                             IF currentDay = 29 AND currentYear MOD 4 <> 0 THEN
71.                                 currentMonth = 3
72.                                 currentDay = 1
73.                             ELSEIF currentDay = 30 AND currentYear MOD 4 = 0 THEN
74.                                 currentMonth = 3
75.                                 currentDay = 1
76.                             END IF
77.                     END SELECT
78.                     IF currentMonth = 13 THEN
79.                         currentYear = currentYear + 1
80.                         currentMonth = 1
81.                     END IF
82.                 END IF
83.  
84.             END IF
85.         END IF
86.     LOOP UNTIL (currentHour = hours2 AND currentMinute = minutes2 AND currentMonth = month2 AND currentDay = day2 AND currentYear = year2)
87.     GetDifference = minutesDifferent
88. END FUNCTION
89.  

[Jaze]

Line 23 in the above code should be

Code: QB64: [Select]

1. daysInMonth1 = 30

, not 20. Didn't notice the typo until I posted the code. I missed it when I tested the code. Sorry.