Bringing up a thread from the past. I'm again working on the same project and I've gotten in over my head, again!

I'm really going way past what I need for this project, but if I'm going in on this I might as well go for broke and try and learn something along the way.

I'm trying to get this to calculate not only the hours per shift, and per week, which I've already managed, but to also calculate how many people are working any given shift. I'd like to make this 'future proof' or at least as close as I can to that.

Here's what I've got so far. Here's a link to the file in question, hosted on my OneDrive.

Execl file found here

Any suggestions?