... Gabriel means "Man of God" or "Might of God".
The Synaxis of the Archangel Gabriel is celebrated on the day after the Annunciation, and a second time on July 13. It was instituted in the ninth century, perhaps to celebrate the dedication of a church at Constantinople. Originally, the Feast was observed on October 16 (Juan Mateos, LE TYPIKON DE LA GRANDE EGLISE).
You look upon God’s glory in heaven,
and bring grace from on high to earth,
wise Gabriel, leader of angels,
minister of God’s glory, and divine defender of the world!
Save and preserve those who cry to you:
“Be our defense, so that no one can be against us!”