Best way to enter data in DB that is spread out date wise
Am I understanding that you pretty much have a work order, and that work order can be worked on for a number of hours on any day, and you want to store how many hours someone worked it each day? So if I work on a project for 2 hours on the 3rd, and 5 hours on the 10th, then it would store 12 hours in the total column?

If that's the case, I would approach it in a more event based method. Have a table for the activity (ActivityID, ActivityName...). Then Have a table for work entries for the activity (ActivityID, PersonWorking, DateWorked, PersonWorked...). The hours will each only be entered into the Work table, and have a view that would sum up each activity and show the days worked along with the total. And as a note, that database systems can usually handle a lot of rows listing 4-5 fields a bit easier than trying to just have 10 years worth of dates in the column headers and just spread everything out.

In my experience it is almost never a good idea to 1)store a computed value based on data in the same record row, and 2)store date data as field names. Unless you have a VERY SPECIFIC set of dates that will apply to all projects/activities, don't use them as field headers.