Good morning.

Is there a way to add or subtract a number (signifying the number of hours)
to a time. For example, in one column I have a time: 12:30PM, in the next
column I have a number -1.5, and I want to say, what is 12:30PM minus the 1.5
hours to equal 11:00AM?

Any help would be greatly appreciated. Thank you very much!