St. Matthew (2:1) tells us that Jesus was born "in the days of King Herod". Josephus (Ant., XVII, viii, 1) informs us that Herod died after ruling thirty four years de facto, thirty seven years de jure. Now Herod was made rightful king of Judea A.U.C. 714, while he began his actual rule after taking Jerusalem A.U.C. 717. As the Jews reckoned their years from Nisan to Nisan, and counted fractional parts as an entire year, the above data will place the death of Herod in A.U.C. 749, 750, 751. Again, Josephus tells us from that an eclipse of the moon occurred not long before Herod's death; such an eclipse occurred from 12 to 13 March, A.U.C. 750, so that Herod must have died before the Passover of that year which fell on 12 April (Josephus, "Ant"., iv, 4; viii, 4). As Herod killed the children up to two years old, in order to destroy the new born King of the Jews, we are led to believe that Jesus may have been born A.U.C. 747, 748, 749. The enrollment under Cyrinus mentioned by St. Luke in connection with the nativity of Jesus Christ, and the remarkable astronomical conjunction of Mars, Jupiter, and Saturn in Pisces, in the spring of A.U.C. 748, will not lead us to any more definite result.
Beginning of the Public Ministry
The date of the beginning of Christ's ministry may be calculated from three different data found respectively in Luke 3:23; Josephus, "Bel. Jud." I, xxi, 1; or "Ant.", XV, ii, 1; and Luke 3:1. The first of these passages reads: "And Jesus himself was beginning about the age of thirty years". The phrase "was beginning" does not qualify the following expression "about the age of thirty years", but rather indicates the commencement of the public life. As we have found that the birth of Jesus falls within the period 747-749 A.U.C., His public life must begin about 777-779 A.U.C. Second, when, shortly before the first Pasch of His public life, Jesus had cast the buyers and sellers out of the Temple, the Jews said: "Six and forty years was this temple in building" (John 2:20). Now, according to the testimony of Josephus (loc. cit.), the building of the Temple began in the fifteenth year of Herod's actual reign or in the eighteenth of his reign de jure, i.e. 732 A.U.C.; hence, adding the forty six years of actual building, the Pasch of Christ's first year of public life must have fallen in 778 A.U.C. Third, the Gospel of St. Luke (3:1) assigns the beginning of St. John the Baptist's mission to the "fifteenth year of the Tiberius Caesar". Augustus, the predecessor of Tiberius, died 19 August, 767 A.U.C., so that the fifteenth year of Tiberius's independent reign is 782 A.U.C.; but then Tiberius began to be associate of Augustus in A .U.C. 764, so that the fifteenth year reckoned from this date falls in A.U.C. 778. Jesus Christ's public life began a few months later, i.e. about A.U.C. 779.
The Year of the Death of Christ
According to the Evangelists, Jesus suffered under the high priest Caiphas (A.U.C. 772-90, or A.D. 18-36), during the governorship of Pontius Pilate A.U.C. 780-90). But this leaves the time rather indefinite. Tradition, the patristic testimonies for which have been collected by Patrizi (De Evangeliis), places the death of Jesus in the fifteenth (or sixteenth) year of Tiberius, in the consulship of the Gemini, forty-two years before the destruction of Jerusalem, and twelve years before the preaching of the Gospel to the Gentiles. We have already seen that the fifteenth year of Tiberius is either 778 or 782, according to its computation from the beginning of Tiberius's associate or sole reign; the consulship of the Gemini (Fufius and Rubellius) fell in A.U.C. 782; the forty second year before the destruction of Jerusalem is A.D. 29, or A.U.C. 782, twelve years before the preaching of the Gospel to the Gentiles brings us to the same year, A.D. 29 or A.U.C. 782, since the conversion of Cornelius, which marks the opening of the Gentile missions, fell probably in A.D. 40 or 41.
The Day of the Death of Christ
Jesus died on Friday, the fifteenth day of Nisan. That He died on Friday is clearly stated by Mark (xv, 42), Luke (xxiii, 54), and John (xix, 31). The few writers who assign another day for Christ's death are practically lost in the multitude of authorities who place it on Friday. What is more, they do not even agree among themselves: Epiphanius, e.g., places the Crucifixion on Tuesday; Lactantius, on Saturday; Westcott, on Thursday; Cassiodorus and Gregory of Tours, not on Friday. The first three Evangelists are equally clear about the date of the Crucifixion. They place the Last Supper on the fourteenth day of Nisan, as may be seen from Matt., xxvi, 17, 20; Mark, xiv, 12 17; Luke, xxii, 7 14. Nor can there be any doubt about St. John's agreement with the Synoptic Evangelists on the question of the Last Supper and the Crucifixion. The supper was held "before the festival day of the Pasch" (John, xiii, 1), i. e. on 14 Nisan, as may be seen from Matt., xxii, 7-14. Nor can there be any doubt about St. John's agreement with the Synoptic Evangelists on the question of the Last Supper and the Crucifixion. The Supper was held "before the festival day of the pasch" (John, xiii, 1), i.e. on 14 Nisan, since the sacrificial day was computed according to the Roman method (Jovino, 123 sqq., 139 sqq.). Again, some disciples thought that Judas left the supper table because Jesus had said to him: "Buy those things which we have need of for the festival day: or that he should give something to the poor" (John, xiii, 29). If the Supper had been held on 13 Nisan this belief of the disciples can hardly be understood, since Judas might have made his purchases and distributed his alms on 14 Nisan; there would have been no need for his rushing into the city in the middle of the night. On the day of Christ's Crucifixion the Jews "went not into the hall, that they might not be defiled, but that they might eat the pasch" (John, xviii, 28). The pasch which the Jews wished to eat could not have been the paschal lamb, which was eaten on 14 Nisan, for the pollution contracted by entering the hall would have ceased at sundown, so that it would not have prevented them from sharing in the paschal supper. The pasch which the Jews had in view must have been the sacrificial offerings (Chagighah), which were called also pasch and were eaten on 15 Nisan. Hence this passage places the death of Jesus Christ on the fifteenth day of Nisan. Again, Jesus is said to have suffered and died on the "parasceve of the pasch", or simply on the "parasceve" (John, xix, 14, 31); as "parasceve" meant Friday, the expression "parasceve" denotes Friday on which the pasch happened to fall, not the before the pasch. Finally, the day following the parasceve on which Jesus died is called "a great sabbath day" (John, xix, 31), either to denote its occurrence in the paschal week or to distinguish it from the preceding pasch, or day of minor rest.