@RayButterwoth Read my answer again. While it was true the Pharisees popularized the Nisan 15 Sabbath in the late second Temple period, at the time Jesus died the Sadducees controlled Temple worship. Herbert W. Armstrong wrote an 80-page doctrinal paper on who controlled Temple worship at the time Jesus died and he has a shorter version also available online. It is titled Pentecost. HWA believes Nisan 15 was a Sabbath though and unfortunately, he was wrong on this count as Nisan 15 was a not a biblically based doctrine.
@RayButterworth Even if the Jews observed Nisan 15 as a Sabbath when Jesus died, it is unlikely (to me at least) that the inspired writers would have recognized it as a Sabbath because if wasn't a Sabbath. There is no evidence anywhere that Nisan 15 was a Sabbath when Jesus walked the earth. HWA believes that the Pharisees regained control of Temple worship sometime around 50 CE.
@RayButterworth After the Pharisees regained temple worship, they set Nisan 15 as a Sabbath as their predecessors had done in the first century BCE. Josephus and Philo held to the Pharisean view and Josephus was a Pharisee and recorded how the Jews celebrated the waving of the Omer on Nisan 16, the day after the annual Sabbath.
file:///C:/Users/DLM/Downloads/Pentecost_Study_Material.pdf The above link will help you understand that the Sadducees controlled Temple worship when Jesus died but it assumes the Sadducees kept the Nisan 15 Sabbath like the Pharisees believed it should be kept. There is no evidence, anywhere, that the Sadducees believed Nisan 15 was a Sabbath. It is ASSUMED but it is not true, Maybe you know some writing from that time period that shows the Sadducees believed Nisan 15 was a Sabbath.
@RayButterworth You claim that John would naturally refer to Nisan 15 as a Sabbath but you offer no proof for that statement. Why would John call Nisan 15 on a Thursday a Sabbath if it were not scriptural to do so? The Sadducees did not believe it was. And you can't prove they did call it a Sabbath. I can't see an inspired writer, writing for the Holy Spirit, the same Holy Spirit that did not call Nisan 15 a Sabbath in the original Scriptures, call Nisan 15 a Sabbath when it clearly wasn't.
@RayButterworth By the way, three days and three nights does not always mean exactly 72 hours just like a day does not always mean 24 hours. Some people work eight hours a day for five days and it is said they worked five days, and it doesn't mean they worked 60 hours. I don't believe Jonah was literally in the sea creature for 72 hours. Those that claim that it must be exactly 72 hours have the burden of proof to show this is so. Jews counted days inclusively so if Jonah was swallowed on Wednesday that would be the first day and Friday would be the third day.
@RayButterworth This means that Saturday would be the third night but it would also be a fourth calendar day. But there is no contradiction because it is said nowhere that Jonah would rise on the third day. If Jesus was literally three days and three nights in the heart of the earth that would contradict the many verses that claim Jesus rose on the third day. Nowhere does the Bible teach us that Jesus rose from the dead the fourth day but Saturday afternoon would be the fourth day. Jews counted their days inclusively so Wednesday would be counted as day one of his death.
@RayButterworth Saturday would be the fourth day of his death.
@RayButterworth Since the scriptures do not declare Nisan 15 to be a Sabbath anywhere, and you claim it is, then the burden of proof is on you to show that it is scriptural.