Formula for determining number of hours?

[Susan]

Does anyone have a formula which would determine number of hours like for
9:00-12:30, or 1:30-3:00 etc. so that I could use result and multiply it
times number of days and have total hours? Guess it would involve conversion
to 24 hr clock?

 

[Bernard Liengme]

If A1 has 9:30 and A2 has 12:15 then =A2-A1 yields a result of 2:45 (2 house
and 45 mins)
I can multiply this by 2
The formula =(a2-a1)*24 yields 2.75 (2 and 3/4 hours)
The formula (A2-A1)+1*(A1>A2) can be used to allow for passing thru midnight
Or use ((A2-A1)+1*(A1>A2))*24
best wishes