Del. Code tit. 5 § 1302
Any banking organization may, at its option, either close or remain open on Saturdays, Sundays and the legal holidays designated in § 501 of Title 1 and holidays observed by the Federal Reserve Bank for the district which includes Delaware. As to any banking organization electing to remain open on any of such holidays, such day or days shall not constitute a holiday within the meaning of the laws of this State, and such banking organization shall incur no liability by reason of remaining open on such holiday. If any banking organization elects to close on any such holidays, any act authorized, required or permitted to be performed at or by such banking organization may be performed on the next succeeding banking day and no liability or loss of rights of any kind shall result from remaining closed, notwithstanding any law of this State to the contrary. This section shall not operate to invalidate or prohibit the doing of any act by any person or banking organization on any of such holidays, and nothing in any laws of this State, in any manner whatsoever, shall affect the validity or render void or voidable the payment, certification or acceptance of a check or any other negotiable instrument or any other transaction by any other person or banking organization, because done or performed during any of such holidays, notwithstanding any other law of this State to the contrary.
5 Del. C. § 1302