When you clone an event, a copy of the event is created. All attributes of the event are cloned except the attachment.
To clone an event from another calendar:
Select the event that you want to clone from any of the calendar views.
A balloon tool tip appears displaying the basic information about the event.
Click Add/View additional Details link.
A new tab is created displaying all the attributes of the event in edit mode.
Click Clone Event.
A Notice window appears displaying the message "Item Successfully Cloned". Click OK. Calendar view will show the cloned event with the same attributes.
Open the cloned event in edit mode to modify the Event details to suite your requirements.
Click Save.