When did Paul go up to Jerusalem with Barnabas and Titus according to Galatians 2:1?

Les teaches that Galatians is Paul's letter to the Gentile churches he established in Asia Minor, now Turkey, and that this setting is about twenty-two years after Pentecost. In Galatians 2:1, Paul says, 'then fourteen years after'—that is, after what took place in chapter one—he went up again to Jerusalem with Barnabas and took Titus with him also. Paul went up by revelation, meaning God had revealed to him the necessity to go. He went to Jerusalem to meet the leaders of Judaism and the believing Jews, the assembly or church at Jerusalem, and he communicated the gospel he preached among the Gentiles. Paul and Barnabas had been called back to Jerusalem because they questioned his going to Gentiles with what they thought was for the Jew. Les notes that the prophetic program had been interrupted.