Most of us keep receipts, and then forget them. Kept reads the receipt for you and works out the dates that matter: the last day to return it, the 14 days to change your mind on an online order, the 30 days to reject something faulty, and when the warranty runs out.
Each receipt becomes a pass, coloured by the date it leads with, with a timeline from the day you bought it. Kept never invents a return period: if a shop doesn't offer one, it says so, and tells you what the law still gives you.