Lewis & Short

trīdŭum, i, n. (sc. spatium) [tres-dies], the space of three days, three days: ubi triduom continuom, Plaut. Mil. 3, 1, 147: hanc hoc triduom solum sinas Esse hic, id. Cist. 1, 1, 106: triduom servire numquam te sinam, id. Mil. 4, 4, 57: bidui’st aut tridui Haec sollicitudo? Ter. And. 2, 6, 9: ut maneas triduom hoc, id. Phorm. 3, 2, 4: decrevit habendas triduum ferias, Cic. Leg. 2, 22, 57: cum tridui viam processisset, Caes. B. G. 1, 38: Clodius respondit, triduo illum, ad summum quatriduo periturum, Cic. Mil. 9, 26: triduo intermisso, Caes. B. G. 1, 26; Plaut. Truc. 2, 3, 16; Plin. 23, 8, 80, § 152; Mart. 2, 6, 12.