Effort per Week starts on Monday when Work Week set to Sunday

In Task Coach version 1.4.2, I have set the Start of work week to Sunday in the Preferences>Features. When I set the aggregate mode to "Effort per week" in the Effort viewer, it shows the time as starting on Monday. Is there a way to get this to start on Sunday?

I think the Effort viewer should summarize the effort for "Effort per week" starting on the Start of Work Week setting. In my case, I would like the "Effort per week" to start on a Sunday.

Is this a bug that I should report?

Thanks
Keith