When the Pharisees and scribes ask Jesus for a sign, he answers that “an evil and adulterous generation seeks a sign; but no sign shall be given to it except the sign of the prophet Jonah. For as Jonah was three days and three nights in the belly of the whale [or “great fish”], so will the Son of man be three days and three nights in the heart of the earth” (Matt. 12:39-40). This prediction seems to contradict the traditional view that Jesus dies on Friday afternoon and returns to life on Sunday morning. Some people therefore suggest alternative explanations (e.g., Jesus dies on Thursday afternoon).
However, the Bible plainly indicates that Jesus’ death takes place on Friday. The second Gospel records that “when evening had come, since it was the day of Preparation, that is, the day before the sabbath, Joseph of Arimathea, a respected member of the council, who was also himself looking for the kingdom of God, took courage and went to Pilate, and asked for the body of Jesus” (Mark 15:42-43). The Greek noun rendered “the day before the sabbath [prosabbaton]” can also be translated “Friday.”
Besides, Jesus himself reveals that he isn’t to remain in the grave for three full days and nights. He tells the disciples that after being “mocked and scourged and crucified,” the Son of man “will be raised on the third day” (Matt. 20:19). If Christ is buried for three full days and nights, he rises again on the fourth day—not the third.
Why, then, does Jesus speak of “three days and three nights” (Matt. 12:40) if he knows that he will vacate the tomb after only two nights? The Lord’s sign-of-Jonah prediction employs a Hebrew idiom. In ancient Jewish speech, even part of a day may constitute “a day and a night.” Thus, Friday afternoon, Saturday, and Sunday morning qualify as three days and three nights.