The "Week summary to date" factbox displays a summary of timesheet hours for a given timesheet period.  
This summary information is misleading during a split week, as the factbox appears to display hours information for the full week, but instead only calculates hours information for days within the split timesheet period.
This form would be more useful if it reported across the full week (not just the split portion of the timesheet period), or hid the days that it was not actually reporting on so that the user was not mislead to think the sum for those days was zero.
See case # 117080916161016 for more information.
Under Review
Ideas Administrator

Thank you for your feedback. Currently this is not in our roadmap; however, we are tracking it and if we get more feedback and votes, we may consider it in the future.

Sincerely, Annette Bruer, PM, Microsoft