does a three year warranty start at the date of purchase
Its 3 years from Mac purchase date. If you buy a Mac on Jan 25, 2010, your original cover expires on Jan 25, 2011. If you buy AppleCare on the day you buy your mac, your cover expires on Jan 25, 2013, If you buy AppleCare on Dec 25, 2010, your cover STILL expires on Jan 25, 2013.