I have a daily log of worked shifts over 12 months period with the following structure:

ShiftStart_DateTime | ShiftEnd_DateTime | Total hours between a shift

01/05/2020 08:00 am | 01/06/2020 9:00 am | 1 days 1 hrs 0 mins

Note: Total hours between a shift Calculated using array formula discussed in this forum

={“Total hours between a shift”;ARRAYFORMULA(IF(ISBLANK(A2:A),"",INT(C2:C-B2:B)&" days “&TEXT(C2:C-B2:B,“h”” hrs ““m”” mins “”")))})

and trying to produce a report to show total hours made on monthly basis i.e.

Month | Total Hours

Jan | 20

Feb | 10

…

Dec | 30

Totals | 60

and I am not sure how to go about.