February 21 in Eastern Orthodox liturgical calendars is a feast day and a day of commemoration of saints and martyrs. Although some Orthodox churches use the Revised Julian Calendar and others use the traditional Julian calendar, the fixed commemorations for their respective February 21 are broadly the same, no matter which calendar is used.
Saint Eustathius of Antioch, Archbishop of Antioch (337)
Hieromartyr Severian, Bishop of Scythopolis in Palestine (452)
Venerable Andreas and Anatolios, monastics of the Church of Jerusalem, disciples of Venerable Euthymius the Great (5th century)
Saint Maximianus of Ravenna, Bishop of Ravenna and Confessor (c. 556) (see also: February 22)
Saint John Scholasticus, Patriarch of Constantinople (577)
Saint Zachariah, Patriarch of Jerusalem (632)
Venerable Timothy of Symbola on Mt. Olympus in Bithynia (795)
Saint George of Amastris, Bishop of Amastris on the Black Sea (c. 805)
Saint Felix of Metz, third Bishop of Metz in France for over forty years (2nd century))
Saint Severus and Sixty-Two Companions, martyrs in Syrmium in Pannonia (3rd-4th centuries)
Saint Alexander of Adrumetum, martyred with others in North Africa (c. 434)
Martyrs Verulus, Secundinus, Siricius, Felix, Servulus, Saturninus, Fortunatus and Companions, martyrs in North Africa, probably under the Vandals (c. 434)
Saint Paterius, a monk, disciple and friend of St Gregory the Great, he became Bishop of Brescia and was a prolific writer (606))
Saint Pepin of Landen, Duke of Brabant, he was the husband of St Itta (Ida) of Metz and the father of St Bavo of Ghent, St Gertrude of Nivelles and St Begga (c. 646)
Saint Ercongotha, daughter of King Erconbert of Kent and St Saxburgh, became a nun at Faremoutiers-en-Brie under her aunt, St Ethelburgh, but reposed very young (660)
Saint Gundebert (Gumbert, Gondelbert), Bishop of Sens in France, later the founder of the monastery of Senones around 660 (c. 676)
Saint Germanus of Granfelden, Abbot of Granfield in the Val Moutier in Switzerland, martyred with another monk, Randoald, while interceding for the poor (677)