use (something) before (some date)
1. To consume or cook with some kind of food or drink before the expiration of its shelf life (which is often indicated by a specific date on the product's packaging). We need to use this chicken before Friday. The jar says to use the mustard before January of this year, but it will be fine if after that if you keep it in the fridge.
2. To make use of something before some specific later date. You've got to use these coupons before Friday or the store won't accept them. These credits will not roll over if you fail to use them before the end of the year.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
use something before something
1. to consume or use something before using something else. Use this jar before that one. This one is older. I used the old one before the one you just bought.
2. to consume or use something before a specified date. I will use this bottle of catsup before May. You should use this one before the date stamped on the bottom.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.