It is currently not configurable and utilizes the start day of the week configured for their Business Unit. If the BU's start date is Monday, then the Sunday before is actually the last day of the prior scheduled week - if the agent was presented the week Sun-Sat instead it then opens up other issues, e.g., shift trading, where the notion of a scheduled week is disjointed from what they are viewing.
A basic question in user experience (UX) for a potential issue is 'is it confusing the first time or is it confusing every time?'. I'd put this in the 'confusing the first time for a subset of users'. Every calendar, including this one, has column headers with the day.
------------------------------
Jay Langsford
VP, R&D
------------------------------