Q. RE: Solving the Three Day Three Night Mystery. So if He died on a Thursday how did we start to celebrate His death on Friday?
A. Here’s a two-part answer. First, as the Church grew it took on more and more of a Gentile personality, and there came a time when it wanted to be free of it’s identification as an offshoot of Judaism. The western branch of the Church wanted to celebrate the Resurrection at the time of the Spring Solstice since there were already pagan celebrations in place (The Feast of Ishtar) and it would fit into the culture better. This is how “Easter” got its name and got disconnected from Passover.
The Friday date came from a misinterpretation of John 19:31 where it says that the day after the crucifixion was a Sabbath. Since the Jewish Sabbath was on Saturday, Gentile logic held that the day before had to be a Friday. But, as I stated in my article, there were two Sabbaths on the weekend that Jesus died, the regular Saturday Sabbath and the the “special” Sabbath John was speaking about. It was the Feast of Unleavened Bread and it fell on Friday, the day before. Therefore Jesus died on Thursday.