Posted previously in this thread
All four gospels agree that Jesus was Jesus was crucified on the day of preparation. Then as now the Greek word for the day we call Friday is paraskeue, which does mean preparation.
The first day of unleavened bread is never called a Sabbath in the OT. It is called עצרת/atzereth, solemn assembly. It is similar to a sabbath but differs in one way, the preparation and cooking of food is specifically permitted.
Exo 12:15-16
(15) Seven days shall ye eat unleavened bread; howbeit the first day ye shall put away leaven out of your houses; for whosoever eateth leavened bread from the first day until the seventh day, that soul shall be cut off from Israel.
(16) And in the first day there shall be to you a holy convocation, and in the seventh day a holy convocation; no manner of work shall be done in them, save that which every man must eat, that only may be done by you.
LXX Exo 12:16 And the first day shall be called holy, and the seventh day shall be a holy convocation to you: ye shall do no servile work on them, only as many things as will necessarily be done by every soul, this only shall be done by you.
That being true, neither 1st nor 7th ULB requires a preparation day as does the weekly Sabbath. There was only one preparation day and one Sabbath in passion week.
Justin [A.D. 110-165.] The First Apology Chap. LXVII
But Sunday is the day on which we all hold our common assembly, because it is the first day on which God, having wrought a change in the darkness and matter, made the world; and Jesus Christ our Saviour on the same day rose from the dead. For He was crucified on the day before that of Saturn (Saturday); and on the day after that of Saturn, which is the day of the Sun, having appeared to His apostles and disciples, He taught them these things, which we have submitted to you also for your consideration.
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Jewish Encyclopedia - DAY
In the Bible, the season of light (Gen. i. 5), lasting "from dawn [lit. "the rising of the morning"] to the coming forth of the stars" (Neh. iv. 15, 17). The term "day" is used also to denote a period of twenty-four hours (Ex. xxi. 21). In Jewish communal life part of a day is at times reckoned as one day; e.g., the day of the funeral, even when the latter takes place late in the afternoon, is counted as the first of the seven days of mourning; a short time in the morning of the seventh day is counted as the seventh day; circumcision takes place on the eighth day, even though of the first day only a few minutes remained after the birth of the child, these being counted as one day. Again, a man who hears of a vow made by his wife or his daughter, and desires to cancel the vow, must do so on the same day on which he hears of it, as otherwise the protest has no effect; even if the hearing takes place a little time before night, the annulment must be done within that little time. The day is reckoned from evening to evening—i.e., night and day—except in reference to sacrifices, where daytime and the night following constitute one day (Lev. vii. 15; see Calendar). "The day" denotes: (a) Day of the Lord; (b) the Day of Atonement; (c) the treatise of the Mishnah that contains the laws concerning the Day of Atonement (See Yoma and Sabbath).E. G. H. M. F.
Jewish Encyclopedia online