Did you know that only last month, this month and the next ten months will have bolded dates in the small navigation calendars? You’ll also need to make the appointments (or all day events) as Busy, Out of Office, or Tentative – items marked as Free won’t bold the calendar.

In current versions of Outlook, appointments in the selected calendar(s) in your mailbox or profile will show bolded dates. This includes your calendars from MSN/Hotmail or a PST file but not shared calendars from other user’s mailboxes.