I was manually counting the months a few years ago and I found this formula today and I hope it can help some of you.
A + B + C x 12 = how many months are between two dates.
where
A = 12- Months in first year
B = Months in last year
C = (First year - last year - 1) x12
Example 1
31-Dec-04 30-Jun-20
1 Jan to 31Dec = 12
A = 12 - 12 = 0
1 Jan to 30 Jun = 6
B = 6
2004 to 2020
C = 2020- 2004 - 1 or
C = 20- 4 - 1
12 C = 180
0+6+180= 186 Months
Example 2, for clarity sake. it is not advisable to use formula if it is something simple like this example. (you will lose time)
01-Apr-96 30-Jun-96
1 Jan to 1 Apr = 3
A = 12 - 3 = 9
1 Jan to 30 Jun = 6
B = 6
2004 to 2020
C = 1996 - 1996 - 1 or
C = 6 - 6 - 1
12 C = -12
9+6-12 = 3 Months
