A coupon expires just before midnight on the date noted on the coupon.
If a coupon lists June 30 as the expiration date, you can use it anytime on June 30, as late as 11:59 pm. It would expire at midnight, and not be valid on July 1. (Of course you can use it anytime before June 30 too.)
Military bases are an exception. On base, coupons are valid 6 months past the written expiration date. When you have coupons that recently expired, you can send them to a couple of different expired coupon collection programs:
http://www.operationexpiration.net/
Note: Don’t send coupons more than a month expired.
Learn more about the parts of a coupon here.
