sell-by date

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The final date on which a perishable product can be legally sold to the public.
• noun idiomatic, by extension Used to indicate that something, or someone, is old and out of date.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a date stamped on perishable produce indicating the date by which it should be sold