The AutoArchive feature that was turned on automatically in previous versions of Outlook is turned off by default on both Outlook 2010 and 2013. You can, however, manually remove old entries from your calendar at any time. If you prefer to have Outlook archive data itself, you can enable the AutoArchive feature and specify when Outlook should archive all of your data, including old emails and calendar events.
Launch Outlook 2013 and click the "File" menu. You don't have to be in the calendar to do this. This opens the Account Information window.
Click the "Cleanup Tools" icon. Select "Archive" from the drop-down menu.
Select your calendar folder in the Archive window. If you have more than one calendar, repeat this process unless your additional calendars are sub-folders in your main calendar. If you marked some entries as "Do Not AutoArchive," you can archive them now by clicking the appropriate check box here. Be sure to note the folder in which your archive will be exported. If desired, you can change that folder by clicking the "Browse" button.
Click the "Date" menu and select a date. All Calendar entries before your selected date will be archived. Click "OK."
Launch File Explorer from your desktop taskbar. Select your "Documents" folder, then click the "Outlook" folder. The archive file is called "outlook.pst."
Click the "File" menu in Outlook, then click "Options" in the left menu to open the Options window.
Select "Advanced" from the left menu in the Options window. Click the "AutoArchive Settings" button on the right.
Click the empty check box beside "Run AutoArchive Every" to enable the feature. By default, Outlook archived all your Outlook data that's over six months old every 14 days. Change any settings as needed and click "OK."