noun
Refers to the date on which a document, license, contract, or similar item becomes invalid.
このクーポンの失効日は来月の末です。
The expiry date of this coupon is the end of next month.
パスポートの失効日を確認してください。
Please check the expiry date of your passport.
Compound of 失効 (shikkō, 'lapse, invalidation') and 日 (bi, 'day').