Jesus said " I will be resurrected after Three Days"(Mark 8:31).
The Bible says "after three days" means " about 5 days".
if you read Matthew 17:1 and Luke 9:28, you can understand this.
"After six days Jesus taketh peter james and john his brother and bringeth them up into an high mountain apart" ( Matthew 17:1).
"And it came to pass about an eight days after these sayings, he took peter and john and james, and went up into a mountain to pray" (Luke 9:28).
As you can see from these two verses , "After 6 days" truly means " about an eight days after". therefore, "after three days" means " about an 5 days ".
Jesus died on Wednesday and resurrected on Sunday in 30 AD.
From Wednesday until Sunday, it means " About an 5 days ".
Jesus was in the tomb on Thursday, Friday and Saturday. It was for three days in the tomb. ( Matthew 12:40).
That is why Sunday was "after three days".( Mark 8:31)
God bless all of you.