Del. Code Ann. tit. 6, § 4-404
A bank is under no obligation to a customer having a checking account to pay a check, other than a certified check, which is presented more than six months after its date, but it may charge its customer’s account for a payment made thereafter in good faith.
5A Del. C. 1953, §§ 4-404; 55 Del. Laws, c. 349; 70 Del. Laws, c. 86, § 4