The Calendar Toolbar:

Reference Chart:

Term/Icon	Name/Alternate Text	Action It Performs
	View By Year	Displays the current yearly calendar.
	View By Month	Displays the current monthly calendar.
	View By Week	Displays the current weekly calendar.
	View By Day	Displays the current daily calendar.
	Listview	Displays all the calendar items in a year as a list.
	Back to Inbox	Takes you back to the Inbox.
	Address Book	Opens the address book for editing.
	Webdisk	Opens your file storage.
	User Preferences	Allows you to alter and personalize your settings.
	Logout	Exits OpenWebMail.

You can also change the year, which will display the dates accordingly. Simply click within the drop menu where it says "2009", and change it to the desired year. The month, days, weeks, and events will now be changed according to that year. The same you can do with the month in the "month" field. You can also use the Left () and Right () arrows, just below the toolbar, for that.

You can find out more about using the Calendar Here.