Q:I was watching your teaching on Jonah tonight and it touched on something that has recently started confusing me. I always hear people saying Jesus rose on the 3rd day, and to me it always seemed that he died on the cross on Good Friday and rose from the dead early on resurrection Sunday. To me that always seemed like two days. And in Matthew 12:38-39 Jesus even said, "For just as Jonah was three days and three nights in the belly of the great fish, so will the Son of Man be three days and three nights in the heart of the earth.” So, was it two or three days?
For modern readers of the Bible it appears very much like Jesus was only in the tomb for two days. But that's because today we reckon "a day" as a 24 hour period. But the Jews in the first century didn't think that way. In the ancient Jewish mind, any portion of a day constituted a full day. That means if I came to visit you at your home, arriving on a Friday evening just before sunset, stayed all day Saturday and then left just after sunrise on Sunday morning, I would say I visited you for three days. In other words, in the first century, a day didn't have to last 24 hours to be considered "a day."
It's the same with the comment from Matthew 12 where Jesus spoke of "three days and three nights." To us that means daytime all the way to nighttime. To the Jews it did not. It was a common Jewish idiom to refer to even a part of a day as “a day and night.”
So you see, sometimes when reading your Bible you have to get into the mind and culture of the speaker/author.