Setting first day of week not working in April 2017 update for TImeslips 2017

The latest update for Timeslips 2017 indicates that it will allow you to set the first day of the working week for reporting purposes.

Fantastic! Except it doesn't. I have applied the update and gone to Setup > General > Aging Periods as indicated in the release notes and there is no option to set the first day of the week.