{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 (h(8870)santo) in  Mr
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.  Lu 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.