Del. Code tit. 1, § 502

No contract made, instrument executed, or act done on any of the legal holidays designated in § 501 of this title shall be thereby rendered invalid, and nothing in that section shall be construed to prevent or invalidate the entry, issuance, service or execution of any writ, summons, confession, judgment, order or decree, or other legal process whatever, or the proceedings of any court or judge or board of canvass on any of such holidays.