Forumla For Creating wedding timeline/Subtracting time

Hi there! I have been scouring the web for a formula but haven't been able to create a worksheet that does exactly what we need. I am a wedding photographer and have been trying to create a worksheet for my brides to help them calculate their wedding day timeline. What we are trying to put together is a way for them to enter in a time (like their ceremony start time example 4:00pm) and have the rest of the timeline auto populate the rest of the timeline by deducting minutes from that original time (or adding).

Example:

They Enter 4pm for the ceremony. Then the worksheet would automatically subtract 1hr (60 minutes) from 4pm and put 3pm for the time we are shooting bridal party photos earlier in the timeline/worksheet and take 90 minutes from 4pm and insert that into "bride gets dressed" section etc... We haven't been able to find the correct formula to subtract/add time in that manner.

Any Ideas?

Thanks so much!

see if the attached hives you what you need?

you are welcome, glad to help let me know if there is anything else i can help with