The Cathedral of the Archangel Gabriel is celebrated by the Orthodox Church twice a year - the day after the Annunciation (April 8) and July 26.
The Archangel Gabriel was chosen by the Lord in order to proclaim to the Virgin Mary, and with Her and to all people, the great joy of the Incarnation of the Son of God. Therefore, the next day after the Annunciation, having glorified the Most Pure Virgin, they thank the Lord and honor His messenger Archangel Gabriel. And the reason for the establishment of the second day of celebration (July 26), as it is believed, was the date of consecration in the 17th century in Constantinople of the temple, erected in the name of the holy Archangel.