Macbook warrenty check

sorry, but the warranty starts at date of purchase. if you bought it and didn't activate it for 13 months, you would have no warranty remaining.

to check where your Mac stands, please visit Check Your Service and Support Coverage Status - Apple Support and sign in with your credentials.

If you have documentation showing that purchase date is incorrect, you can ask Apple to fix it: About the purchase date or expiration date for your AppleCare agreement - Apple Support.

As it states "Keep your sales receipt and proof of coverage in a safe place" — Apple does not retain that information.

To update your purchase date, send Apple your proof of purchase