How do I generate a random hour slot between two time periods in Excel?

Trying to generate a start time for a random hour slot between two time periods in Excel. For example, if the time period is between 06:48 and 09:36, the start time generated could be any value between 06:48 and 08:36 (to allow for the hour slot).

I will need this formula to apply to lots of different periods of time so the easier the formula is to manipulate the better.

Cheers