Yes - Friday, Saturday, and Sunday is three days but you are forgetting that it included "three nights" and He was already risen before dawn on Sunday.
Jesus rose exactly three days and three nights after His burial (just before sunset; see Matt. 27:46 and Mark 15:34), His resurrection would have been the very end of the weekly Sabbath at sunset. On Friday, the preparation day for the weekly Sabbath, the women prepared spices for His embalming (Luke 23:56) then kept the weekly Sabbath. When they came to the tomb early Sunday morning, He was already risen "as it began to dawn toward the first day of the week"; "very early in the morning the first day of the week. . . at the rising of the sun"; "Now upon the first day of the week, very early in the morning,". He rose exactly three days and three nights from His interment ( a full 72 hours) at sunset as the weekly Sabbath ended.
I believe the three full days and three nights and you prefer the Friday to Sunday - whatever! - He rose - and that is the "weightier matter"!
I'm not intending to beat a dead horse as it were, but I personally find this stuff interesting and I think it helps to clarify things. There doesn't need to be confusion on issues like this because the biblical accounts give enough detail to pretty clearly show what happened and when.
Lets look at what the gospels say. First keep in mind that the Jews had a different system of counting time than the rest of the Roman world. The Jews counted days from evening to evening where as the gentiles counted days from morning to morning. As a result when the gospels speak of hours of the day, some confusion may arise because depending on the audience they were writing to, or their own way of thinking, they may have used either the Jewish reckoning or the Roman reckoning.
In Matthews account of the crucifixion he tells us that as Jesus was on the cross, darkness came over the land at the "6th hour" until the 9th hour, and Jesus died at the "9th hour"
This was a supernatural darkness that covered the land for three hours while Jesus was on the cross.
Matthew further tells us that in the evening Joseph of Arimathea retrieved Jesus body and put it in the tomb (27:57)
Matthew then reports that the next day, which he identifies as the day after "the day of preperation". The chief priests went to Pilate to ask him to put a guard on the tomb. This poses a question because there are actually two days of preperation that this could be referring to. We know that this is occuring at the time of the feast of unleavened bread and there was a day of preperation for the feast of unleavend bread during which the house had to be cleaned and all leaven removed.
But there was also a day of preperation for the weekly sabbath (ie friday) so which one is matthew referring to?
Matthew 28 begins the account of the resurrection and he states that the women came to the tomb after the sabbath at dawn on the first day of the week. Further he tells us that there was an earthquake and the tomb was opened at that time (dawn on the first day of the week).
In Marks gospel...
in 15:6 we are told that Pilate had the custom of releasing a prisoner to the people "on the feast" (the feast being passover). Usually the people would ask for a political prisoner.. someone who had been imprisoned for opposing the Romans etc. Not an actual Criminal.
So Pilate used that custom to try and release Jesus. He offered up Jesus and Barabbas who was a criminal. It is a very interesting note that the name Barabbas literally means "son of the father". This scene is reminiscent of the sacrifice on the day of atonement when two sheep are brought into the temple, the sacrifical lamb, and the scape goat. The scape goat was let go outside the camp and the sacrifical lamb was of course offered up to God. Here we see two 'sons of the father' Jesus and Barabbas, one of them sinless who was offered up, and the other a sinner who was let go.
This also implies, however, that Jesus' trial is taking place on the Passover because pilate invoked his custom of releasing a prisoner on the feast.
Mark then tells us that Jesus was put on the cross at the 3rd hour, and he agrees with Matthew that darkness came over the land at the 6th hour until the 9th hour and Jesus died at the 9th hour. The exact same time description that Matthew used.
Then Mark tells us that Joseph of Arimathea collected the body at evening (just as Matthew said) but he adds the statement "since it was the day of Preparation, that is, the day before the Sabbath".
Remember in Matthew we saw that he mentioned the priests coming to Pilate to ask for a guard on the tomb on the day after the day of preperation, but we weren't sure which day of preperation he was talking about. Mark tells us unequivocally that they day of preperation was the day of preperation for the weekly sabbath. In other words, it was Friday.
Mark's account of the resurrection, again agrees with Matthew's, however it does add a bit of detail. Matthew just said that the women came and the tomb was opened around dawn.
Mark specifically states that the women went to the tomb "when the sun had risen".
Matthew's description mentions the women coming, but it also mentions that there was an earthquake, an angel came and rolled away the stone, and the Roman guards were either rendered unconscious or struck with terror so that they 'became like dead men'.
Mark fleshes out some of the detail showing that the women arrived after sunrise, but they found the stone already rolled away.
Thus it seems that the earthquake and the angel rolling away the stone happened at sunrise, and the women arrived shortly there after.
Luke's account and his time descriptions agree with Mark and Matthews. He mentions the same darkness at the 6th and 9th hours. He mentions Joseph of Arimathea coming to bury the body and that it was the day of preperation. He, however, adds the detail that "the sabbath was beginning" so they hurried to get him in the tomb and didn't fully prepare the body. Then he says...
"On the Sabbath they rested according to the commandment"
This provides further confirmation that this was the weekly sabbath, so the day of preperation was friday and the sabbath was saturday.
Luke agrees with Mark and Matthew saying that the women came to the tomb on the first day of the week 'at early dawn'.
Lastly we have the gospel of John.
John's gospel account agrees with the others, but there is one apparently contradiction. John says that Jesus was still before Pilate at the 6th hour. All the others say Jesus was on the cross and that the darkness began at the 6th hour.
The confusion here is because of the variable ways that time was reckoned. Jews usually reckoned 12 hours of day and 12 hours of night. The 6th hour of the day was around noon.
The romans had a couple different ways of doing it. They did sometimes use hours of the day and hours of the night as the Jews did and in this way 6th hour would be noon just as among the Jews, but they also reckoned the day beginning at midnight, the system we use to this day. This was the official reckoning, thus the sixth hour of the day in this view was around 6 AM or sunrise.
John mentions several times that Jesus was on the cross during the day of preperation and he also tells us that the sabbath was a high sabbath. This meant that it was a sabbath that occured on a feast day, in this case the feast of unleavened bread.
John's account of the resurrection says that the women came to the tomb early on the first day "while it was still dark". Some people have tried to argue from this that it happened actually on saturday night (since Jewish days begin at sundown).
However, this does not contradict what the other gospels all say, that it happened at sunrise, at dawn. If you've ever been outside at dawn when the sun rises, it is still dark. Its twilight.
So.. if we piece all this together, we find out that Jesus' trial before Pilate was coming to an end at about 6 AM on the day before the sabbath (Friday), he was put on the cross at about 9 AM on Friday. At noon on Friday the supernatural darkness covered the land and at about 3 PM on Friday, Jesus died. His body was collected and put in the tomb just before sundown on Friday, probably around 6 PM.
On saturday the priests when to Pilate to get the guards assigned to the tomb.
Early in the morning on Sunday, at dawn, the tomb was opened and an earthquake occured, very shortly after dawn, the women arrived at the tomb and met the angel and Jesus.
Looking at the question of three days and three nights, consider this. It was fortold that Jesus would be in the tomb three days and three nights, BUT it was also fortold that he would arise on the third day.
How is that possible? If he arises on the third day, he can't be in the tomb on the third night.
Thus if you take the literal understanding of three days and three nights, then the prophecies themselves and Jesus own words conflict with each other.
If you are going to be in the tomb three days and three nights, then by definition you have to rise on the fourth day, not the third day. Unless you count any portion of a day as a full day. Which is what the Jews did.
This actually occurs several places in scripture where it says something went on for three days and nights, and then on the third day it ended.
Talmud Pesach 4a states that any part of a day is considered as a whole day. This is specifically written in regard to periods of mourning the dead. Thus it was Jewish practice to count even only a small part of a day as a whole day (including the night).