missjo:
Muttley why are you counting the period of Jesus hanging on the cross as part of the days and nights?

The prophesies do clearly state ... in the grave for three days and three nights.

The grave refers to the place of death, meaning death. The period where He hung on the cross dead was also of the grave.

missjo:
1. Regarding your opinion on the Sabbath, sir it's common historical knowledge that the High day of the passover in Jewish culture held on Thursdays, and it is also referred to as Sabbath. If John in his gospel had not even noted this particular sabbath was the high day, scholars would naturally have assumed it was a Friday - Saturday count. Just the insertion of the "high day" reference is enough to squash any doubt that the count started on 6pm Wednesday.
.......
3. You of all people should know that most scriptures can always be confirmed by reference to another.
In which case, anyone who still believes that Jesus was buried on a Friday and not found in the sepulchre on Sunday morning will definitely have a hard time proving that he spent 3days & 3nights as prophesied. Prophesies from God were mostly fulfilled literally and I doubt you will find any in the entire compilation of the present Bible that wasn't fulfilled literally, not to mention when it now involved a Prophesy of God himself becoming flesh, dying and resurrecting.

By the way, sixth hour and ninth hour in the Jewish clock is 12noon and 3pm respectively. I just inserted this here for anyone who wants to confirm the exact time darkness came over the land while Jesus hung on the cross an also the exact time Joseph of Arimathea enters the story to talk to Pilate.

1. So the "High day" is no longer Wednesday but Thursday?

The day after Passover is a Holy day decreed by God in HIs Old Law - Leviticus 23 vs 4 - 8 - the First Day of the Festival of Unleavened Bread.

Passover and Festival of Unleavened Bread
4 “These are the Lord’s chosen festivals. You will announce the holy meetings at the times chosen for them.
5 The Lord’s Passover is on the 14th day of the first month[a] just before dark.
6 “The Lord’s Festival of Unleavened Bread is on the 15th day of the same month. You will eat unleavened bread for seven days.
7 On the first day of this festival, you will have a special meeting. You must not do any work on that day.
8 For seven days, you will bring sacrifices offered as gifts to the Lord. Then there will be another special meeting on the seventh day. You must not do any work on that day.”

Count of what exactly started on Wednesday when Jesus Christ Himself said that He would be in the grave for 3 days and rise on the 3rd day?
2. Burials cannot take place on Holy days aka Sabbath days. So, if Jesus Christ was not buried on Friday, as the stories clearly state, on what day would Jesus Christ have been buried? The day of Passover when we are told He was having the Last Supper with His disciples? Or the "High day" you keep brandishing wherein no Jew was allowed to do any work in?