By default in Microsoft Office Outlook 2007, the work week is set from Monday through Friday with a work day extending from 8 A.M. to 5 P.M.. The first day of the week in Calendar is Sunday.
You can choose the days of the week that are a part of your work week, the time when your work day starts and ends, and the day of the week that you want to be the start of your week.
Change your Calendar work days
1. On the Tools menu, click Options.
2. Click Calendar Options.
3. Under Calendar work week, select the check boxes for the days that are a part of your work week. Clear the check boxes for the days that are not a part of the work week.