Mark 14:12

The Jews commonly referred to the first day of the combined Passover and Unleavened Bread feasts as the feast of Unleavened Bread. [Note: Josephus, Antiquities of . . ., 2:15:1.] Mark clarified for his Gentile readers that this was the day the Jews slew the Passover lamb, namely, the fourteenth of Nisan. This would have been Thursday, April 2. Mark could say the Passover was two days away on Wednesday (Mark 14:1) because the Jews ate the Passover lamb between sunset and midnight on the evening of the day they slew the lamb. For the Jews this was two days later since they began each day with sunset. The disciples had to prepare to eat the Passover within Jerusalem (Deuteronomy 16:5-6) that very evening.