There are four historical/archeological pinpoints that must be considered when constructing a chronology of Paul’s ministry and writings.
The death of Aretas IV, king of Nabetea—between A.D. 38 and 40 (2 Cor 11:32-33; Acts 9:23-25).
Paul visited Jerusalem three years after his conversion, according to Galatians 1:18. A terminus ad quem (Latinterminus “limit” + ad “up to” + quem “which” = the latest possible date of an event) for this visit would have been A.D. 40, because Aretas IV died in that year, according to coins and inscriptions. Paul had escaped from Damascus and gone to Jerusalem while Aretas was still alive, thus before A.D. 40
The expulsion of Jews from Rome by Claudius—A.D. 49 (Acts 18:2).
The text says that Paul met Aquila and Priscilla in Athens who were from Rome because Claudius had commanded all the Jews to leave Rome. Suetonius, chief secretary to the emperor Hardrian (A.D. 117-38), wrote a biographical account of the twelve caesars, in which he said, “Because the Jews at Rom caused continuous disturbances at the instigation of Christ’s, he expelled them from the city.” There are other citations referencing the event. However, this is the best reference as it is closest in time to the dating of the expulsion.
Gallio’s proconsulship in Achaia—began in May/June, A.D. 51 (Acts 18:12).
We have fragments of a letter sent from Claudius to the city of Delphi, either to the people or to Gallio’s successor. The letter is dated to A.D. 52. Since proconsuls normally held office for one year, and these provincial governors were required to leave Rome for their posts not later than the middle of April, Gallio probably began his term of office in May of A.D. 51. Since Paul arrived in Corinth eighteen months earlier than this appearance before Gallio, he would have entered Corinth in the winter of 49/50—perhaps in January of A.D. 50. This would coincide well with the recent arrival of Priscilla and Aquila from Claudius’ expulsion in A.D. 49.
Procuratorship of Festus in Judea—began in May/June, A.D. 56 (Acts 24:27).
Important to note that for a long time most scholars have dated Paul’s visit to Festus in A.D. 59-61. However, a coin was recently found that dates Festus’ accession to A.D.56.