A.T. Robertson Commentary Luke 22:1

"Now the feast of unleavened bread drew nigh, which is called the Passover." — Luke 22:1 (ASV)

The Passover (πασχα) Both names (unleavened bread and passover) are used here as in Mr 14:1. Strictly speaking the passover was Nisan 14 and the unleavened bread 15-21. This is the only place in the N.T. where the expression "the feast of unleavened bread" (common in LXX, Ex. 23:15, etc.) occurs, for Mr 14:1 has just "the unleavened bread."Matthew 26:17 uses unleavened bread and passover interchangeably.

Drew nigh (ηγγιζεν). Imperfect active. Mr 14:1; Matthew 26:2 mention "after two days" definitely.