If you note from the other synoptic gospels you find that the women arrived at the tomb (now empty) at dawn. HE was already risen. Please also note there were no guards when they arrived. (otherwise they would have not gotten close to the tomb) Roman guards stood in 3 8-hour watches, and since it was recorded that they went to the temple priests who paid them to lie that the body was stolen.
So the women got there probably around 5 - 6 am and the guards were gone meaning that the resurrection could have occured no earlier than 9 pm Saturday evening (which in Jewish timekeeping is the First Day). The fact that both Jewish and Gentile Messianic believers seem to have made a big deal of the Havdala service (starts at sundown Saturday evening - beginning of the First Day) would make sense if the resurrection occured on saturday evening.
Not proof but evidence pointing to that scenario.
You are right ..there were no eye-witnessess...all we have is scripture 1Cor.15v3,4.
First we have Jesus' own sign/prediction Mat.12v38,40 of 3 days and 3 nights. Here people go mad saying it could mean anything , a portion of a day , a few minutes, a few hours ...whatever fits your own understanding. But Jesus explains in Joh.11v9,10 that there are 12 hours in each period making it 72 hours in all. Since we are talking about "biblical evidence" we must take the bible serious...and not insert human ideas.
We know from scripture Jesus was put into the tomb just before sunset on the day of 'preparation which was before the beginning of the 'High day/Sabbath mentioned in Joh.19v14,31. IF you take this to be a Friday and count 72 hours then the resurrection would have been on monday sunset.
But the last sunset before sunday morning when the women arrived at the empty tomb was on the Sabbath , the weekly Sabbath ....no matter what time the women arrived sunday....Jesus was risen and not there.
So because He was 'discovered' risen on sunday people "assume" he rose on sunday (careless or deliberate false reasoning and a great opportunity to deceive). but all this points to is the arrival of the women at that time...it is not saying Jesus rose at that time. To God this means a difference but maybe not to ignorant man.
The problem that you have Beta is proving Jesus was raised on Saturday, and you must prove without a doubt with simplicity that Jesus showed himself on Saturday or the prophecy is not of any value,
Scripture is very clear Jesus showed himself openly on Sunday to confirm he was risen, not Saturday.
The problem that many have in proving the "worldly" "theology" of in the Tomb 3days 3nights in Mat.12 v38,40, They have to prove that without a doubt in the scripture, that Jesus was in the Tomb the whole time of the 3days and 3nights. They must do it with Simplicity in not destroying eyewitness accounts.
They must also prove by the scripture Mat.12 v38,40 means what it says, a transalation using the Greek meaning of the words used in that Scripture.
They also have to prove that Jesus was not dead while he was in the tomb, since the scripture is relating to a Dilemma and experience that Jonah was having in the great fish, while Jonah was Alive.
In order to prove Wednesday Death and in the tomb 3 days nights, they have to prove Jesus being in the tomb on Wednesday and that he arose on Saturday , and they must also address and disprove many Clear scriptures in the NT of the actual timed events, such as Jesus being placed in the Tomb on the preparation day of the Seventh day Sabbath Commandment.
They must also prove that the scriptures term THIRD DAY in the NT means SATURDAY and therefore they must disprove Luke’s account of the Disciples testimony in the walk to EMMAUS, them saying to Jesus “it was The THIRD DAY since the suffering and Death, that being clearly the First of the week Sunday.
They must also prove that Jesus SHOWED HIMSELF OPENLY on SATURDAY to confirm and declare the completion and the end of the PROPHECY, which is the most important part of the fulfillment of any prophecy. Therefore they must do it with eye witness testimony in the Bible and the bible alone and not scientific math Calculation for the simplicity that one will believe it..
Eye witness testimony is the Bibles most accurate account of what happened, without the eye witness testimony all one has proven is circumstantial evidence and that’s OK as long as it does not destroy eye witness accounts. The Death and resurrection time is given in eye witness Testimony, If one ventures into disproving the eye witness account, They must prove their theory and do it with simplicity, not leaving any doubt in the mind of the believer. The bible is not about placing doubt in the mind of the Believers. One must take into account not to destroy eye witness account and leave any doubt in the ordinary believers mind. We must remember many are poor and uneducated in astronomy about stars and the moons, they do not carry scientific calculators in their pockets to prove scientific men. They rely on simple eye witness accounts of what Honest Men of God told them what happen.
The reason the scriptures are so BELIEVABLE, the most simplest of Mind can understand them. God is not an author of Confusion; Satan is the author of Confusion. If one would just go back to the Beginning of the bible and read the simplicity of the words when God told Adam not to eat form that one tree, and then read how the Devil gave a sermon to Eve and had a Parlay of words with Eve while her husband was not there, shows how Satan Confused the simplicity of Gods command, in the end she ended up believing Satan’s words over the simplicity of God’s word.
The bottom line is that the 3day 3night tomb theory of WEDNESDAY death of Jesus Christ and the resurrection on SATURDAY leads to so much confusion of the simplicity of the Bible; it destroys the simplicity of eye witness testimony. Much like what evolutionist do with the flood account in the bible, these people use Men of the world to prove theory over Gods simple words of eye witness accounts of Noah, Noah also being a Man, but was God Chosen Disciple,
Evolutionist instead of just believing in the simple testimony of the Bible , they seek answers elsewhere to prove men of the world are more accurate than Gods word.