The Bible does not use calendar days of the week such as Saturday and Sunday. However, traditionally the Jewish Sabbath is said to run from Friday evening to Saturday evening forming the seventh day (day of rest). The Passover occurs during the first month (called Nisan) of the Jewish Torah year which is not the same as the Jewish calendar year. Nisan corresponds to around Mar/April of the American calendar rather than January.
In Bible terminology a day begins in the evening at sunset and ends the next day at sunset. Thus we can view a day as having a beginning evening and an ending evening. Jesus could not have eaten and been killed in the same evening given the time it took for his trial and actual crucifixion. The dual evening concept resolves this dilemma. Jesus ate his Last Supper at the beginning evening part of Nisan 14 (Passover). Jesus was crucified on the ending evening part of Nisan 14 (Passover). This concept of the two evening means Jesus did not violate the Exodus 12:6 commandment to kill the Passover lamb in the evening.
Nisan 14 for that year was on the preparation day for the weekly sabbath which was a high sabbath for that year being also the first day of the feast of unleavened bread. For John 19:31 says “that Sabbath was a high day”. By that he means for that year the first day of the Feast of Unleavened bread fell on that day. Note that John does not say that day was a high sabbath but rather that sabbath was a high day. I mention this because some claim that the first day of unleavened bread is a sabbath referred to as a high sabbath. However, in Leviticus 23 and elsewhere the first and last day of the feast of unleavened bread is no where identified as a sabbath but only as a day of holy convocation and rest from servile work; the word sabbath is not used. Yes the functionality of the Sabbath is partially present but the word sabbath is not used. Indeed, when the word sabbath is used it is understood that no type of work is to be done not just no servile work.
Mark 15:25,33-34 says Jesus was crucified at the 3rd hour (9am) and died at the 9th hour (3pm). This took place on the preparation day which is the day before the weekly Sabbath. In the Book entitled the Jews Wars Josephus says “So these High-priests, upon the coming of that feast which is called the passover, when they slay their sacrifices, from the ninth hour till the eleventh…”. So Jesus death approximated the normal slaying of the sacrifices.
As the feast of unleavened bread approached (Luke 22:1), which is also called the Passover, Judas planned his betrayal. When the day of unleavened bread came when the Passover lamb is to be killed, Jesus sent Peter to kill a lamb to prepare the Passover (Luke 22:7-8). They then ate it in the upper room as Christ last supper (Luke 22:1-22). Soon after his last supper Jesus was arrested (Luke 22:39, 47, 54). It is done at the beginning of the day of preparation or right before it. It is what we know as Thursday evening which is in Bible time the beginning of Friday; thus, the probable beginning of Jesus three day reference.
The next morning at daylight they took Jesus to the Sanhedrin Council for trial (Luke 22:66). They then took him before Pilate (Luke 23:1). It is now early morning on the preparation day which will lead to his crucifixion at 9:00 AM that morning on what we know as Friday.
Jesus was placed in tomb on the day of preparation for weekly Sabbath (G4521, Sabbaton) per Matthew 27:62; Luke 23:54; and John 19:14, 31, 42 which is the day before the Sabbath (G4315, proSabbaton) per Mark 15:42. On the Sabbath (G4521, Sabbaton) the people rested (Luke 23:56) on what we know as Friday evening to Saturday evening and most likely until daylight on what we know as Sunday morning. For early in the morning on the first day of the week (G4521, also Sabbaton, here indicating interval between two Sabbath Days) the women came to the tomb and found Jesus gone (Matthew 28:1, 6). Note that since in bible rendering of time the night part of a day precedes the daylight part. This means that the first day begin at sunset on the seventh day of the week. This means that Jesus could have arisen during the night part of the first day of the week and his resurrection discovery taking place at sunrise or daylight part of the first day of the week.
Key Scriptural References: Mark 15:25,33-34; Matthew 27:59-64; John 13:1-5; John 19:14,31,42; Mark 15:42-43; Luke 22:1,7-8,15,20; Luke 23:52-56; Matthew 28:1, 6; Acts 20:7; 1 Corinthians 16:2
