Jesus said, “The Son of Man be three days and three nights in the heart of the earth” (Mt. 12:40). Paul writes that Jesus was raised “on the third day” (1 Cor. 15:4). But Jesus was placed in the tomb on Friday and raised on Sunday morning. This was hardly three days; it was more like a day and a half. Critics argue that this is a blatant error in the resurrection account.
However, the phrase “three days and three nights” is a common Jewish idiom meaning “spanning three calendar days.” It is a common feature of biblical chronology that “the part equals the whole.” For instance, in Acts 19:10 and 20:31, Paul says two years in one; three years spanned in another.