April 1 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 April 1 are broadly the same, no matter which calendar is used.
Saints Hermes and Theodora the martyrs (132)
Saint Melito of Sardis, Bishop of Sardis (177)
Martyrs Gerontius and Basilides (3rd century)
Saints Alexander, Dionysius, Ingeniani, Panteros (or Pantainos), Parthenios and Saturninus the Martyrs.
Saint Makarios of Pelekete, Abbot of Pelekete Monastery (820)
Saint Procopius of Sázava, Abbot of Sázava in Bohemia (1053) (see also: July 4 - West)
Venantius, a Dalmatian bishop whose relics were brought from Spalato to Rome in 641 (c. 255)
Saint Walric (Walericus, Valéry), Abbot of Leuconay (Saint-Valery-sur-Somme) (622)
Saints Caidoc and Fricor (Adrian), Welsh missionaries (7th century)
Saint Dodolinus of Vienne, Bishop of Vienne in the Dauphiné in France (7th century)
Saint Cellach (Cellach mac Congaile), Archbishop of Armagh in Ireland, previously the Abbot of Iona in Scotland and founder of the Monastery of Kells (815)
Saint John Shavteli of Salosi (John of Black Mountain), Georgia (12th-13th century)
Saint Eulogius of Salosi, Georgia, (Eulogius the Prophet), Fool-for-Christ (12th-13th century)
Martyr Abraham of Bulgaria, on the Volga, Wonderworker of Vladimir (1229)
Saint Gerontius of the Kiev Caves, Canonarch of the Kiev Caves (14th century)
Saint Euthymius the Wonderworker, Archimandrite of Suzdal (1404)
Saint Pachomius (Romansky), Archbishop of Roman and Galați, Moldavia, and monk of the Kiev Caves (1724) (see also: April 14 - Romanian)