Dormition fast takes place on August 01, 2021. The Feast of the Dormition is preceded by a two-week fast, referred to as the Dormition Fast. From August 1 to August 14 (inclusive) Orthodox and Eastern Catholics fast from red meat, poultry, meat products, dairy products (eggs and milk products), fish, oil, and wine. The Dormition Fast is a stricter fast than either the Nativity Fast (Advent) or the Apostles' Fast, with only wine and oil (but no fish) allowed on weekends.
As with the other Fasts of the Church year, there is a Great Feast that falls during the Fast; in this case, the Transfiguration (August 6), on which fish, wine and oil are allowed. In some places, the services on weekdays during the Fast are similar to the services during Great Lent. Many churches and monasteries in the Russian tradition will perform the Lenten services on at least the first day of the Dormition Fast.
During the Fast, either the Great Paraklesis or the Small Paraklesis are celebrated every evening except Saturday evening and the Eves of the Transfiguration and the Dormition. The first day of the Dormition Fast is a feast day called the Procession of the Cross (August 1), on which day it is customary to have a crucession and perform the Lesser Sanctification of Water. (With material from: Wikipedia)