Liturgical calendar (Lutheran) in the context of "Lord's Day"

Pentecost (also called Whit Sunday, Whitsunday or Whitsun) is a Christian holiday that takes place on the 49th day (50th day when inclusive counting is used) after Easter. It commemorates the descent of the Holy Spirit upon the Apostles of Jesus, Mary, and other followers of the Christ, while they were in Jerusalem celebrating the Feast of Weeks, as described in the Acts of the Apostles (Acts 2:1–31). Pentecost marks the "Birthday of the Church".

Pentecost is one of the Great feasts in the Eastern Orthodox Church, a Solemnity in the Roman Rite of the Catholic Church, a Festival in the Lutheran Churches, and a Principal Feast in the Anglican Communion. Many Christian denominations provide a special liturgy for this holy celebration. Since its date depends on the date of Easter, Pentecost is a "moveable feast". The Monday after Pentecost is a legal holiday in many European, African and Caribbean countries.

Eastern Lutheranism (also known as Byzantine Lutheranism or Byzantine Rite Lutheranism) refers to Eastern Protestant Lutheran churches, such as those of Ukraine and Slovenia, that use a form of the Byzantine Rite as their liturgy. It is unique in that it is based on the Eastern Christian rite used by the Eastern Orthodox Church, while incorporating theology from the Divine Service contained in the Formula Missae, the base texts for Lutheran liturgics in the West.

Eastern Lutherans use the Julian calendar for the calendar and thus observe feast days and liturgical seasons, such as Great Lent, in a fashion similar to Orthodox customs. As such, many Byzantine Lutheran holy days are shared with those of the Eastern Orthodox Church; in addition, Eastern Lutheran churches are constructed in accordance with Byzantine architecture. Posture during worship, such as bowing, is identical to that in other parts of Eastern Christianity. Within Byzantine Rite Lutheranism, the calendar of saints includes persons esteemed in Eastern Christianity, such as John Chrysostom and Nestor the Chronicler, as well as those specific to the Lutheran Church, such as Lucas Cranach the Elder and Martin Luther.