There is a lot of debate in some circles over when Jesus was crucified. I don’t mean over the year, though there is that debate too. This one is sparked by Jesus’ words in Matthew 12:40:

For as Jonas [Jonah] was three days and three nights in the whale's belly; so shall the Son of man be three days and three nights in the heart of the earth. 

The day that Jesus was resurrected is not, to my knowledge, in dispute. Mark 16:9 says very clearly:

Now when Jesus was risen early the first day of the week, he appeared first to Mary Magdalene, out of whom he had cast seven devils.

The general understanding is that the Jewish people worship on Saturday because it was “the seventh day” referenced in their law (Exodus 20:8-11). This makes the resurrection day of Sunday to be pretty well established and this is the reason that the discussion goes the opposite direction. People wonder what day Jesus was crucified on. Earlier this year, before Easter, I had spent some time trying to explain that Christians were not necessarily wrong to count Jesus’ death as being on Friday. An entirely different set of people has brought the issue up this week, so I’m going to attempt to summarize why I think Friday is correct. Jesus was taken down from the cross before the Sabbath. This is verified in John 19:31 (see also Mark 15:42 and Luke 23:54):

The Jews therefore, because it was the preparation, that the bodies should not remain upon the cross on the sabbath day, (for that sabbath day was an high day,) besought Pilate that their legs might be broken, and that they might be taken away.

Jesus ate Passover with his disciples (Luke 22:15) as the Jewish day begins at dusk. The rest of the Jews were still preparing for and observing the Passover. John 19:14,15:

And it was the preparation of the passover, and about the sixth hour: and he saith unto the Jews, Behold your King! But they cried out, Away with him, away with him, crucify him. Pilate saith unto them, Shall I crucify your King? The chief priests answered, We have no king but Cæsar.

It’s slightly possible that I’m misunderstanding Passover tradition but I don’t believe so. I’ve made this point to others before, including Jews, and have not been corrected despite asking specifically. The symbology is fantastic that Christ was crucified on the day that the Jews remembered God passing them over in his judgment! In any case, the day after Passover was considered a Sabbath according to Numbers 28:16-18. Some people use this extra Sabbath to “prove” that Thursday or Friday was also regarded as a Sabbath that week. I’ll get to this a little further on. Jesus was taken off the cross the same day that he was crucified. See John 19:42 (also verse 31, above):

There laid they Jesus therefore because of the Jews' preparation day; for the sepulchre was nigh at hand.

It appears that the Sabbath (15th day of of the first month in the Hebrew calendar) fell on Saturday that particular year. Luke records that the women rested one day, as commanded, and then returned on the first day of the week (Sunday). Luke 23:54-24:2:

And that day was the preparation, and the sabbath drew on. And the women also, which came with him from Galilee, followed after, and beheld the sepulchre, and how his body was laid. And they returned, and prepared spices and ointments; and rested the sabbath day according to the commandment.
Now upon the first day of the week, very early in the morning, they came unto the sepulchre, bringing the spices which they had prepared, and certain others with them. And they found the stone rolled away from the sepulchre.

The definite article is used. Only one Sabbath passed between Jesus being buried and his resurrection, which was definitely on Sunday. He was buried the same day that he was crucified. This only leaves one option, and that is that he was crucified on Friday. This means that the question of whether Christians can count is a good one. At most, 36 hours could have passed between when Jesus was buried and when the sun broke the sky and Jesus walked out of the grave. I had to do some digging around to satisfy my own questions on this matter a while back. It turns out that there is a good explanation. The Jewish people have traditionally held that a part of a day counts as the whole. Here is what John Lightfoot, a rabbinical scholar from the 1600’s had to say based on his research of Hebrew culture:

[The Son of man shall be three days and three nights in the heart of the earth.] 1. The Jewish writers extend that memorable station of the unmoving sun at Joshua's prayer to six-and-thirty hours; for so Kimchi upon that place: "According to more exact interpretation, the sun and moon stood still for six-and-thirty hours: for when the fight was on the eve of the sabbath, Joshua feared lest the Israelites might break the sabbath: therefore he spread abroad his hands, that the sun might stand still on the sixth day, according to the measure of the day of the sabbath, and the moon, according to the measure of the night of the sabbath, and of the going-out of the sabbath; which amounts to six-and-thirty hours."
II. If you number the hours that passed from our Saviour's giving up the ghost upon the cross to his resurrection, you shall find almost the same number of hours; and yet that space is called by him "three days and three nights," when as two nights only came between, and only one complete day. Nevertheless, while he speaks these words, he is not without the consent both of the Jewish schools, and their computation. Weigh well that which is disputed in the tract Schabbath, concerning the uncleanness of a woman for three days; where many things are discussed by the Gemarists concerning the computation of this space of three days. Among other things these words occur; "R. Ismael saith, Sometimes it contains four Onoth sometimes five, sometimes six. But how much is the space of an Onah? R. Jochanan saith either a day or a night." And so also the Jerusalem Talmud; "R. Akiba fixed a day for an Onah, and a night for an Onah: but the tradition is, that R. Eliezar Ben Azariah said, A day and a night make an Onah, and a part of an Onah is as the whole." And a little after, R. Ismael computeth a part of the Onah for the whole.
It is not easy to translate the word Onah into good Latin: for to some it is the same with the half of a natural day; to some it is all one with a whole natural day. According to the first sense we may observe, from the words of R. Ismael, that sometimes four Onoth, or halves of a natural day, may be accounted for three days: and that they also are so numbered that one part or the other of those halves may be accounted for a whole. Compare the latter sense with the words of our Saviour, which are now before us: "A day and a night (saith the tradition) make an Onah, and a part of an Onah is as the whole." Therefore Christ may truly be said to have been in his grave three Onoth, or three natural days (when yet the greatest part of the first day was wanting, and the night altogether, and the greatest part by far of the third day also), the consent of the schools and dialect of the nation agreeing thereunto. For, "the least part of the Onah concluded the whole." So that according to this idiom, that diminutive part of the third day upon which Christ arose may be computed for the whole day, and the night following it.

There are other places in the Bible where this is demonstrated also, especially in what we call the Old Testament (which was all that the Jewish people had). Here is Rehoboam, Solomon’s son in II Chronicles 10:5,12:

  5 And he said unto them, Come again unto me after three days. And the people departed.
   12 So Jeroboam and all the people came to Rehoboam on the third day, as the king bade, saying, Come again to me on the third day.

In a way, we even use the same language in our own culture. If you read the command about remembering the Sabbath day to keep it holy because on it God rested from creating the world, you would interpret it that you should rest for a full 24 hours. If somebody worked for only one hour of that time, has he “kept the sabbath day”? The answer is “no.” By working even a short amount of time on that day, you are considered guilty of breaking the observance of the day. I think that, rather than this being an inaccuracy (or the innability to count), that it is a sign of the culture behind what we are reading. It is an anomaly of translation which I, personally, find fascinating.