I don't know if this will help, but here goes... If I was designing this fresh, I would have three tables, Students, Projects, and Student-Project-History.
The project table would contain a project ID, project description, and a begin and end date for the entire project. (Projects probably start and end sometime, right?)
The student table would have their ID and name.
The student-project-history table would have the Student ID, a Project ID, a Sequence number, and begin and end dates. The sequence number covers you if a student participates in the same project more than once. You would have to handle the max of ten projects per month some way; can project involvement extend beyond month end? Or do you start fresh each month?
The current project for a student would have a beginning date but no ending date; every other project would have both dates. So, when a student changes projects, you update the "old" current project by adding the ending date, then write a new record that becomes their "current" project.
Now, the textboxes. What do they do? My guess is that you are trying to show which students participated in a given project, graphically...
Also, do you need to handle school days versus calendar days?