I have a form which shows me a total of hours used per person i.e. [time from]-[time to] i.e. number of hours used in a format of hh:mm.
I have managed to calculate the total of each person but cannot seem to get my head around calculating all the number of hours for all the people in a specific area.

I have managed to calculate the total of each person but cannot seem to get my head around calculating all the number of hours for all the people in a specific area.
