The Work Week view displays the days that are selected in the Backstage view for calendar options.
To customize the days that are part of your work week, do the following:
Click the File tab.
Under Work time, for Work week, select or clear the check boxes for the days that you want to be displayed.
Tip: In Calendar, you can quickly change the number of days that appear (1 to 10 days). Press Alt and then a single digit, such as Alt+3 for a three-day display or Alt+0 for 10 days.