Dates are according to the old calendar.
September 8 — Nativity of the Most Holy Mother of God
September 14 — Elevation of the Precious and Life-Giving Cross of the Lord
November 21 — Entry of the Most Holy Mother of God into the Temple
December 25 — Nativity of Christ
January 6 — Theophany/Baptism of the Lord
February 2 — Presentation of the Lord
March 25 — Annunciation of the Most Holy Mother of God. (Sometimes before or after Palm Sunday. This depends wholly on the date of Pascha).
Last Sunday before Pascha — Entry of the Lord into Jerusalem (also called Palm Sunday)
40 days after Pascha (Thursday) — Ascension of the Lord
50 days after Pascha — Pentecost – Descent of the Holy Spirit
August 6 — Transfiguration of the Lord
August 15 — Dormition of the Most Holy Mother of God