The third day is significant not withstanding references in the Old testament that the Messiah will resurrect on the third day.
(Daniel 9 : 24 – 27; Deuteronomy 18:15; Ezekiel 37 : 24 ; 26: 27; Haggai 2:6:9; Hosea 11:1, Jeremiah 31: 5; Micah 5: 2)
In the New Testament the name of Jesus occurs as the person who will resurrect on the third day.
One may ask why Jesus did not resurrect on Good Friday? In many faiths the deceased person is buried on the same day of death, before midnight.
Or why did Jesus not resurrect on the Sabbath which was a Saturday? Why did Jesus resurrect on Easter Sunday? Could there have been another reason why the Resurrection occurred on Easter Sunday that we may not have considered?