As for the source fields that your form will map to, yes you may be looking at having to create each time slot manually. The initial effort may be large, but after that infrastructure is in then you can have more flexibility in how you design your logic for calculating totals for a day, for the whole week, etc. If you go with repeating sections (you could make a repeating section for each week or day or within one day), then I think you can do sum calculations over the repeated items as well to get totals, and auto-populate a total field based on rules. This video is the one I was referring to in my last post which is an excellent intro to applying repeating tables to a business requirement. And here's another video that demos a timesheet in InfoPath that doesn't use repeating sections but also has integration with Excel. Hopefully that gives you some useful ideas.