By default, Outlook reminds you of appointments 15 minutes before the fact. You can change that warning time to suit your own schedule (or turn it off altogether).
- From the Tools menu, choose Options
- Click the Preferences tab.
- In the Calendar section, select a new time from the Default Reminder drop-down list. You can enter a custom time; just be sure to identify it as minutes, hours, days, or weeks.
- Click OK.