{Cometh} (ginetai). Futuristic use of the present middle
indicative. This was probably our Tuesday evening (beginning of
Jewish Wednesday). The passover began on our Thursday evening
(beginning of Jewish Friday). {After two days} (meta duo
h(886d)eras) is just the familiar popular mode of speech. The
passover came technically on the second day from this time. {Is
delivered up} (paradidotai). Another instance of the futuristic
present passive indicative. The same form occurs in verse  24 .
Thus Jesus sets a definite date for the coming crucifixion which
he has been predicting for six months.