The Non-Work Day Option

  Use the Non-Work Day option on the Mark submenu to
  mark a particular day as Non-Work.  Choosing Non-Work
  Day causes the day to appear in standard Calendar font
  (bold).

  Once you choose Non-Work Day, the marked days continue
  to be displayed as Non-Work even if you change the setting
  for that day of the week to Work in the dialog box of the

  General...  menu item on the Options menu.

  Additional topics:

  *   The Normal Day Option

  *   The Special Day Option

  *   The Work Day Option

  *   The Default Option

  *   Marking Days and Weeks

  *   Customizing General Settings