How do we calculate the number of hours between 2 given time?
For example, how many hours between 2pm and 5pm?
The easiest way to do this is simply subtraction: 5 - 2 = 3 hours.
Having said that, if the number of hours is across noon, say between 11am and 2pm, you would need to convert 2pm into 24 hour format, before working out the subtraction. That would be 14 - 11 = 3 hours.
However, if the number of hours is across midnight, say 11pm to 2am, it would be a 3 step process as follows:
First, you would need to work out the number of hours for day 1. This is done by converting 11pm into 24 hour format, and work out the subtraction from midnight. This would be 24 (midnight) - 23 = 1 hour.
Next, you would work out the number of hours for day 2. This is a little tricky, as midnight for day 1, represents 0 hours for day 2. Therefore, the subtraction would be 2 - 0 = 2 hours.
Finally, you would need to add both answers together 1 + 2 = 3 hours.
That is quite a lot to handle. As such, a more structured way, though more time consuming, would be to count onwards from the starting time:
11pm ------->12midnight------->1am------->2am
1hr 2hrs 3hrs
We need to note that it is the time between, therefore we count the time from 11pm to 12midnight as 1 hour (as above).