The commemoration of the finding of Christ's Cross by St. Helena and its elevation by St. Macarius for veneration. Celebrated on September 14th, this feast is both joyful (for the Cross's discovery) and solemn (remembering Christ's suffering). Flowers and basil are often blessed, and a strict fast is observed.

The central worship service of the Orthodox Church, celebrating the Eucharist (Holy Communion). Usually celebrated on Sundays and feast days, the Divine Liturgy consists of the Liturgy of the Word (scripture readings) and Liturgy of the Faithful (Eucharistic prayer and communion). The most common forms are the Liturgies of St. John Chrysostom and St. Basil the Great.

A brief night prayer service traditionally celebrated at midnight, anticipating the coming of Christ as the Bridegroom. Also called Mesonyktikon, this service includes psalms that speak of watching and waiting for the Lord, particularly Psalms 50 and 118. The Midnight Office emphasizes spiritual vigilance and the need to be always ready for Christ's return. In monastic communities, it is celebrated between Compline and Matins. The service includes the Creed and often commemorates the departed.

A lengthy service combining Vespers and Matins, traditionally celebrated on the eve of Sundays and major feasts. The All-Night Vigil includes the singing of "Lord, I Call," the Magnificat, the Great Doxology, and numerous psalms and hymns. This service prepares the faithful spiritually for the upcoming feast.

The descent of the Holy Spirit upon the Apostles fifty days after Pascha, marking the full revelation of the Holy Trinity and the beginning of the Church's mission in the world. During Vespers, special kneeling prayers are offered and the church is adorned with greenery. This feast celebrates the completion of Christ's saving work and the outpouring of the Holy Spirit upon all believers. From this day forward, the Sundays of the year are numbered from Pentecost, signifying the continual life and growth of the Church in the grace of the Spirit.

Brief prayer services traditionally celebrated at specific times of day: First Hour (6 AM), Third Hour (9 AM), Sixth Hour (noon), and Ninth Hour (3 PM). Each Hour includes psalms, troparia, and prayers appropriate to that time of day. These services sanctify the day and connect us to Christ's Passion, as they commemorate specific moments in His crucifixion and death.

The commemoration of the Virgin Mary's miraculous appearance in Constantinople, when she spread her veil over the praying Christians to protect them from enemies. Celebrated on October 1st, this feast is especially beloved in Slavic Orthodox churches. It emphasizes the Theotokos's continuing intercession and protection of the faithful.