Submitted timesheets still take today's date into account

[SeanKilleen]

Repro:

• Supervisee's timesheet has the last day as a "blank day" because they were over on hours and thus took off.
• Supervisee's timesheet is otherwise balanced.
• Supervisee submits timesheet a day early
• Supervisor runs summarizer on the submitted timesheet.

Expected behavior: The timesheet should show as balanced

Actual behavior: The timesheet looks like it is 8 hours "over", because it is incorrectly assuming that the blank day has not been entered yet, even though we're looking at a submitted timesheet.