Trying to calculate times used in planning convoys and cannot seem to make the calculations work (because of mixed formatting?): There are several of them.

1. Calculate arrive times as follows: The arrive time at the SP is the same as the SP time. To calculate the arrive time at the first CP, take the distance from the SP to the first CP, divide by the planned rate of march, and multiply by 60 (minutes). Add this amount of time distance to the arrive time at the SP to determine the arrive time at the first CP.

and now the problems start:

Distance from SP to first CP: 10 km
March rate: 50 KMIH
Solution: 10 ÷ 50 = .20 hours x 60 = 12 minutes

If the arrive time at the SP is 0800, then the arrive time at the first CP will be 08:12.

ISSUE: when I do the calculations on a worksheet the formula cells do not accept h:mm formatting and do not add the 12 minutes to 0800 (or 8 AM) and throughout the entire rest of the solution set to compute arrival times, add in rest times, and fuel or maintenance stops the units of time just will not add up.


Distance from Start Point (SP) to first Check Point (CP)


KM March Rate
KMIH 10 50 Time to arrive at CP1
(formula) 12 00:12 '=((C2/D2)*60)

SP DEPART TIME CP 1 ARRIVAL TIME 8 8.00
The CP 1 arrival time should be 08:12 and not 8.00.
There are many more instances where the arithmetic works with numbers, but not with any thing formatted as time or custom [h]:mm or any time like format.

I appreciate any help that can solve the problem I'm having.

Thanks in advance.