September 1st is the Byzantine New Year 7525. Western Christians begin their new liturgical year on the First Sunday of Advent. The Greek Church, today.
Historically, “the First Ecumenical Council established that the Church’s year would begin on September 1st, continuing the practice of the Roman Empire at that time. For centuries, the beginning of the civil year coincided with the Church year, but later changed, first in western Europe, then in Russia in the time of Peter the Great.”
IN the Divine Liturgy we sing the following trope:
O Lord, Maker of the Universe, who alone has power over the seasons and times, bless this year with your bounty. Preserve our country in safety. Keep your people in peace. Through the prayers of the Mother of God, save us. (from the Troparion)