Every evening (hotan opse egeneto). Literally, whenever evening came on or more exactly whenever it became late. The use of hotan (hote an) with the aorist indicative is like hopou an with the imperfect indicative (eiseporeueto) and hosoi an with the aorist indicative (hēpsanto) in Mar 6:56. The use of an makes the clause more indefinite and general, as here, unless it renders it more definite, a curious result, but true. Luk 21:37 has the accusative of extent of time, “the days,” “the nights.” The imperfect tense he (or they) would go (exeporeueto, exeporeuonto) out of the city suggests “whenever” as the meaning here.