Is there any significance in the fact that Cornelius has his vision at three in the afternoon?
Acts 10:3 (ESV)
3About the ninth hour of the day he saw clearly in a vision an angel of God come in and say to him, “Cornelius.”
In the Jewish calendar, the ninth hour of the day (three in the afternoon) was a time of prayer.1 Since Cornelius is a God-fearing Gentile, he has learned to adopt the old covenant Jewish practices for piety. He was most likely praying when he had a vision.2
3 About the ninth hour of the day he saw clearly in a vision an angel of God come in and say to him, “Cornelius.”