How to change the settings for the reminders
Reminders alert you to upcoming calendar items such as appointments and meetings. By default, reminders occur 15 minutes before the start of these calendar items. However, you can increase or decrease the default reminder time.
You could change the reminder time to receive notifications when it's convenient for you.
Note: Even when you change the default reminder time, you still have the choice to specify a custom reminder time for each calendar item that you create.
To change the settings for the reminders you need:
Click the File tab.
Click Options.
Click Calendar.
Under Calendar options, next to Default reminders, click a new time.
Click OK.