Conference Scheduling - By Minute

Hi. I am planning a speaking schedule. I need two columns, the time of the presentation, and the length of the presentation.

The length of presentation needs to change the time listed, by the minute.

We have each session listed as a separate group, so I need to be able to put the starting time of the session in the first box of the time column of each group, then the rest of the times to be automatically assigned based on the length of the presentations before.

Could someone help me with the formula that would make this happen?

I have put an example from a spread sheet below.

While monday has rows and columns it is not a spreadsheet, so thinking of it as one is likely to result in significant headache. Formulas cannot span rows for example, or reference other items directly.

You can connect items between boards, or summarize subitems to their parent item. Groups can have a total for a column at the bottom, but not a “top item” which data flows to.

Is this a workflow you are going to repeat time and time again or a one off event?