Need simple formula that produces non-duplicate number representing pairs of time.

What formula could define a number derived from a pair of start stop times that will never be same as derived from any other pair of start stop times. I've wondered if SQRT(ATime)+SQRT(BTime) would do it?

Thank you FDibbins for the welcome and quick reply? In the attached you'll see that rows 2,12, and 22, columns I through O have a formula that is intended to produce a unique number specific to the time pairs that produced it.
The formulas in rows 12 and 22 don't work. Does the formula in row 2 work? It adds the squareroots of the two times (start and stop) associated with that shift. I don't care what formula produces the unique number, but I just don't want a formula that could produce the same number from a different pair of times. As you see I use the number to mark with "1" every shift. If they appear on the same line then they are duplicate shifts on different days of the week, reflected in the freq. column, which I reference elsewhere to produce a recommendation for another program. For example, you'll notice all start/stop pairs are unique except the 9 am to 10 am pairs on Tuesday and Thursday