Numbers Formulas/Functions

I am wondering if there is a way to add or subtract from an hour of day. I am a wedding planner and would like to make a template for wedding timeline. For example, 5:00 PM is the ceremony, + 30 minutes from ceremony start time, cocktail reception begins, + 1.5 hours from ceremony start time, guests invited to dinner. Trying to streamline my business to make it more efficient.

Thanks in advance for your help, and I apologize for my ignorance!
H