Calculating between to time ranges

@RBK2.... We don't know what values are in C8:C11. Based on your expectation, I assume that C8 and C9 are the same date, and C10 and C11 are times that are 1 hour apart.

But the key is: how are the values in C10 and C11 derived?

I see no error if we manually enter two times, for example 1:01 AM and 2:01 AM.

So I assume, for example, that C6 is 10/17/2021 1:01 AM and C7 is 10/17/2021 2:01 AM, and the formulas in C8:C11 are:

C8: =INT(C6)
C9: =INT(C7)
C10: =MOD(C6,1)
C11: =MOD(C7,1)

Then, your INT formula does indeed return 0.983333333333333 (+ 3.33E-16) for my example.

Since you want integer minutes (divided by 60), you should do the following:

=ROUND((C9-C8+C11-C10)*1440,0)/60

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Note.... Round to zero decimal places because that is the precision that you want (duh!).

Do not round to an arbitrary number of decimal places like 10, because that might not always work.

In fact, for my example, ROUND((C9-C8+C11-C10)*1440,10)/60 returns 0.999999999941667 (- 3.33E-16), not exactly 1 as you want.

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PS.... This is not limited to times "between" 12:00 AM and 1:00 PM. I get the same result when the times in C6 and C7 are 1:01 PM and 2:01 PM.

So if you still have questions, please follow the instructions at the top of the webpage to attach an Excel file that demonstrates the problem, with appropriate formulas and data.