Calculate a delay

[Rickinnocal]

Hi all, I have two columns, one for date and one for time.

I want to calculate the time between two events in hours, which may be more than 24hours.

So if A1, A2 etc is a time, and B1, B2 etc is a date, what I want to do is add the time and date together and calculate the difference.

I thought =((A1+B1)-(A2+B2)) would work, but it doesn't. Even =A1+B1 gives #VALUE!

Is there any sort of "absolute time" I can use?

 

[Rickinnocal]

OK, found the problem, the dates had been entered in UK format, (27/01/2021) and Excel wasn't recognizing them as dates.