A Wednesday date of crucifixion is untenable, for at least three reasons. First, if Jesus died on Wednesday, then the women would not have gone to the tomb Wednesday. There would have been the time on Friday to do that, and they certainly would not have waited. In fact, when Lazarus died, one of the women actually told Jesus He couldn’t go to the tomb because by this time - four days after his death - Lazarus would have a terrible stench. It would have been four days since his death on Sunday morning, and so even if they had for some inexplicable reason not gone on Friday, the women would not have gone on Sunday.
Second, the timing would be all off for a Wednesday crucifixion, in terms of the calendar. You’ve suggested Jesus died in 31, but in the year 31, Nisan 14 - the day you’re suggesting He died - was not on a Wednesday. Now let me note that it is possible it was on a Wednesday, if the Jews had added a thirteenth month that year. Wednesday crucifixions would have been possible in 28 and 35, both dates on the extreme ends of the window we have to work with, and in 34.
Third, the Roman guards were posted to prevent Jesus from rising
"on the third day," according to Matthew’s Gospel, because up until that time His followers could steal His body and claim He had risen. If Jesus rose “on Saturday at sunset, which was the beginning of the first day of the week,” He would be rising on the fourth day, not the third. The guards may not have been there any longer. Most importantly, we know that the women approached on Sunday morning. The Wednesday theory holds that they didn’t know He had risen Saturday night, but this isn’t the problem. The problem is that by this time, it was the fourth day.
Those women could cry until the cows came home that Jesus had risen, and the Jewish establishment wouldn’t listen. He said He’d rise on the third day, or after three days and three nights. At this time, it was past the third day, and so by that prophecy of Jesus they could say He had failed to fulfill His words. Even if they took the prophecy that He would rise after three days and three nights, they could easily claim that the body had been stolen. After three days and three nights is, taken literally, is so general a time frame that the body could have been stolen at any time after the third day passed. The establishment would not have accepted this.
Jesus offered His prophecy as a sign - He would rise on the third day, when it was predicted. He gave a very specific prediction so that the fulfillment would be unmistakable.
Consequently, for anyone interested I’m actually working on an analysis of the timing of Jesus crucifixion right now, and I’ll post the link here when I am done.
Peace and God bless