'Ninth' in the Bible

Now Peter and John were going up into the temple at the hour of prayer, being the ninth hour .

He saw in a vision openly, as it were about the ninth hour of the day, an angel of God coming in unto him, and saying to him, Cornelius.

And Cornelius said, Four days ago, until this hour, I was keeping the ninth hour of prayer in my house; and behold, a man stood before me in bright apparel,