1. Click the Mail Drop-down menu in the top left corner, select Calendar from the menu. The Calendar will open to the monthly view by default. The are several view types.
2. In the top left corner, click Create or double click on any day.
3. Select its type: Appointment, reminder, task or note.
4. Select a calendar where you want this event added.
5. Select more options.
6. Under the date and time, check the box next to All day and complete the rest of the form.
7. Click Save.
Note: You'll see all-day events at the top of the page for that day.