A Greek adverb meaning on the morrow, on the following day, the next day. From epi (upon) and aurion (tomorrow). Used throughout the Gospels and Acts to mark the day after significant events, including the day after Jesus' baptism, the day after the Triumphal Entry, and the day after the resurrection.
The repeated use of epaurion in John's Gospel — especially in the opening chapters — creates a sequence of days that culminates in the wedding at Cana and the beginning of signs. John 1:29, 35, 43 — "the next day" — marks a progressive revelation: John points to the Lamb, disciples begin following, Philip is called. In the passion narrative, "the next day" after the Triumphal Entry is the day Jesus cleanses the temple. The morrow always brings a new act of God. The resurrection turns the Jewish sabbath into the first day of a new creation: the epaurion becomes the Lord's Day, the sign of the age to come breaking into the present.