The Calendar portlet can be used for several purposes:
administrators can communicate internal or public events
faculty members can communicate course events
group members can communicate group events
students can add their own personal events
There can be several calendars of events available related to the context in which the calendar appears (such as an Academics calendar, an Athletics calendar, etc.).
When you subscribe to other calendars, the events from those calendars are added to yours. Also, when you have subscribed to a calendar, and that calendar is updated, the updates are also sent to all who have subscribed to the calendar.
You can also import and export events (in CSV format) and have those events also be displayed on your calendar. Therefore, the Calendar portlet allows you to have just one calendar in which all of your related events are displayed.
The administrator of your portal must give you permission to administer both calendars and events. Depending on your permissions you may see zero or more of the following links in the calendar portlet:
Add an Event (upper right-hand corner of the calendar screen)
Click on the 
Add
an Event link from the Calendar portlet
Enter the name of the event and a description
Select the calendar on which the event will be displayed
You may also create another calendar on this
same screen by clicking on the Add
a Calendar link
Select the Start and End Date and time for the event
Select the frequency of the event
Click the Save button
You will need to create a file from your Microsoft Exchange Calendar to store all of your events that will need to be imported:
Go to File, Import and Export from Microsoft Exchange
The Import and Export Wizard will appear
Select Export to a file and click Next
Select Comma Separated Values and click Next
Select the Calendar folder from which to export and click Next
Enter the name of the exported file and click Next
Now you can proceed with actually importing these events into your calendar:
Click on the Full Size Calendar link from the Calendar portlet
Click on the Manage Calendars link
Click on the Import Events from an external source link
Click on the Browse... button and locate the .csv file that you created and saved from Microsoft Exchange
Select the calendar to which these events will be imported from the Import To drop-down menu
Click the Save button
Your imported events will now appear on your calendar
Click on the Full Size Calendar link from the Calendar portlet
Click on the Export Events for this view link
Save the exported .csv file
When you click Manage Calendars from the Calendar portlet the following screen displays:
From here you can:
Add a Calendar
Import Events from an external source
View subscriptions
When you click the Add a Calendar link, the Add/Edit Calendar View displays:
Provide a calendar name and description for the new calendar.
Click the Browse Shared Calendars link to display the Subscription Center:
From here you can browse calendars and subscribe to any that are of interest.
Given the correct permissions, you can also click on a date in the calendar to edit its events.
Click on the 
wrench icon from the main Calendar
screen and select the Preferences
tab.
You may choose to either view the daily event or be able to add a new event whenever the day link is clicked from the calendar.
Default Maximized Calendar View
You may choose from one of the following calendar views:
Day
Week
Month
Year
Event List
You can choose the start day for your calendar by selecting it from the drop-down list of days.
You can select the hour of the day in which the display for your calendar will start.