Scripture is definitive on this...
Ask a Protestant believer why they accept Sunday as the Lord’s Day. The number one answer you will hear is that since Jesus arose on Sunday, the Christian Lord’s Day was changed from Saturday to Sunday.
However, the truth is that the Bible does not tell us directly which day of the week Jesus was crucified. But the Bible does tell us what day of the week Jesus arose, within about ± 1-hour. The account is in the gospel of Matthew:
Matthew 28: 1 – 2: Now after the Sabbath, as it began to dawn toward the first day of the week, Mary Magdalene and the other Mary came to look at the grave. 2 And behold, a severe earthquake had occurred, for an angel of the Lord descended from heaven and came and rolled away the stone and sat upon it. (NASB)
From these verses it is clearly understood that Jesus was resurrected just as the Sabbath was ending and the new day was beginning. That would be Saturday, just as the sun was setting. (A day ended and a new day began at sunset in the New Testament.)
Now consider the words of Jesus in Matthew 12:40: For as Jonah was three days and three nights in the belly of the great fish, so will the Son of Man be three days and three nights in the heart of the earth (NKJV).
Count backward 3-days and 3-nights from Saturday at sunset, and you will arrive at Wednesday afternoon as the sun was setting. This is a compelling argument for a Wednesday crucifixion. Matthew 28:1-2 and Matthew 12:40 should be enough, by themselves, to definitively determine the day of Jesus’ crucifixion to be Wednesday. Sadly these verses are ignored by most Bible students; instead the traditional belief is that Jesus was crucified on a Friday.
The Friday argument is this:
Jesus is considered to be in the grave for three days, although not three complete days. This argument rationalizes that a part of a day can be considered as a full day. Since Jesus was in the grave for part of Friday, all Saturday, and part of Sunday, then he can be considered to have been in the grave for three days. Also, since the body of Jesus was missing on the first day of the week, the assumption is made that Jesus arose on the first day of the week, Sunday, morning.
Mark 15:42 notes that Jesus was crucified "the day before the Sabbath." If this Sabbath was the weekly 7th day Sabbath, i.e. Saturday, then that understanding leads to a Friday crucifixion.
Matthew 16:21 and Luke 9:22 say that Jesus would rise the third day; therefore, he wouldn't need to be in the grave a full three days and nights. Note that the preposition “on” is not found in the Greek manuscripts but many English translations add the preposition “on” to the definite article “the,” i.e., "the" becomes "on the." These translations actually insert theology into the translation. Fortunately there are still many translations that do not add words to support a particular understanding regarding the day Jesus was crucified. For example, the KJV, NKJV, Holman Christian Standard, ASV, GNT, and Young’s literal translation do not add the preposition “on” to this verse. Furthermore, Mark 8:31 says that Jesus will be raised "after" three days.
There is also a Thursday argument:
This view argues that there are too many events occurring between a Friday burial and Sunday morning resurrection. Proponents point out that this is especially a problem when the only full day between Friday and Sunday was Saturday, the weekly Sabbath. An extra day eliminates this problem.
Thursday advocates reason by saying that if the crucifixion day is Thursday then three days later would be Sunday. With this reasoning it can be said that Sunday morning was 3-days later, even though technically, only 60-hours (2.5 days) had passed.
This argument at least recognizes that the Friday argument is illogical but it also fails to satisfy the timeline given in Scripture.
Additional evidence for the Wednesday Argument:
There were two Sabbaths during the crucifixion week. The first Sabbath was the first day of the 7-day Feast of Unleavened Bread. This special day was referred to as a high Sabbath. This special Sabbath followed the Passover (Lev. 23:4-8). The second Sabbath that week was the normal weekly 7th Day Sabbath.
After the first Sabbath, the women purchased spices─ after the Sabbath (Mark 16:1). The Wednesday view holds that this "Sabbath" was not the seventh day Sabbath. Note that in Luke 23:56, the women who had purchased spices after the first Sabbath, returned and prepared the spices then "rested on the Sabbath" (Luke 23:56). The Wednesday understanding argues that the women could not purchase spices after the Sabbath, yet prepare those spices before the Sabbath—unless there were two Sabbaths.
With this view a Thursday crucifixion is not possible because the high holy Sabbath would have begun Thursday at sundown and ended at Friday sundown—at the beginning of the weekly Sabbath or Saturday. Purchasing the spices after the first High Sabbath would have meant they purchased them on the 7th Day Sabbath, thus breaking the 7th Day Sabbath.
The Wednesday argument does not violate the biblical account of the women and the spices and holds to a literal understanding of Matthew 12:40 that Jesus would be in the ground 3-days and 3-nights, for a total of 72-hours. The high Sabbath, after Passover, occurred on Thursday. The women purchased spices on Friday (after the High Sabbath) and returned and prepared the spices on the same day. They rested on Saturday, which was the weekly Sabbath, then brought the spices to the tomb early Sunday. This argument promotes Jesus’ crucifixion on a Wednesday afternoon with a burial near sundown.
One argument against the Wednesday view is the assumption that the disciples who walked with Jesus on the road to Emmaus did so on the same day of his resurrection (Luke 24:13). The disciples, who did not recognize Jesus, told him of Jesus' crucifixion (24:21) and said, "Today is the third day since these things happened" (24:21). Sunday is four days after Wednesday. One could respond with the explanation to begin counting from Wednesday, sunset, at Christ's burial, which begins the Jewish Thursday; three days from Thursday is Sunday.
But there is a far better explanation. Luke 24:21 says “…besides all this, today is the third day since these things happened.” “All this” refers to everything that happened concerning the crucifixion. “All this” includes when the tomb was sealed and a guard being stationed the following day, Thursday (Mathew 27:62 – 66). Counting three days from Thursday again takes us to Sunday. Once again Scripture is in perfect harmony.
The “Emmaus Road” argument that assumes Jesus arose sometime Sunday morning is therefore a faulty assumption.
Matthew 28: 1-2 should be enough, by itself, to definitively determine the day of Jesus’ crucifixion. Based upon the totality of Scripture and logic the only reason a Protestant believer would chose to accept Friday or Thursday as the day Jesus was crucified would be blind obedience to tradition.