A chronology of Jesus aims to establish a timeline for the events of the life of Jesus. Scholars have correlated Jewish and Greco-Roman documents and astronomical calendars with the New Testament accounts to estimate dates for the major events in Jesus's life. Two main approaches have been used to estimate the year of the birth of Jesus: one based on the accounts in the Gospels of his birth with reference to King Herod's reign, and the other by subtracting his stated age of "about 30 years" when he began preaching. Most scholars, on this basis, assume a date of birth between 6 and 4 BC. Three details have been used to estimate the year when Jesus began preaching: a mention of his age of "about 30 years" during "the fifteenth year" of the reign of Tiberius Caesar, another relating to the date of the building of the Temple in Jerusalem, and yet another concerning the death of John the Baptist. Hence, scholars estimate that Jesus began preaching and gathering followers around AD 28–29. According to the three synoptic gospels Jesus continued preaching for at least one year, and according to John the Evangelist for three years. Five methods have been used to estimate the date of the crucifixion of Jesus. One uses non-Christian sources such as Josephus and Tacitus. Another works backwards from the historically well-established trial of the Apostle Paul by the Roman proconsul Gallio in Corinth in AD 51/52 to estimate the date of Paul's conversion. Both methods result in AD 36 as an upper bound to the crucifixion. Thus, scholars generally agree that Jesus was crucified between AD 30 and AD 36. Isaac Newton's astronomical method calculates those ancient Passovers (always defined by a full moon) which are preceded by a Friday, as specified by all four Gospels; this leaves two potential crucifixion dates, 7 April AD 30 and 3 April AD 33. In the lunar eclipse method, the Apostle Peter's statement that the moon turned to blood at the crucifixion (Acts of the Apostles 2:14–21) is taken to refer to the lunar eclipse of 3 April AD 33; although astronomers are discussing whether the eclipse was visible as far west as Jerusalem. Recent astronomical research uses the contrast between the synoptic date of Jesus' last Passover on the one hand, with John's date of the subsequent "Jewish Passover" on the other hand, to propose Jesus' Last