The notation Old Style or (OS) is sometimes used to indicate a date in the Julian Calendar (which is used by churches on the "Old Calendar"). The notation New Style or (NS), indicates a date in the Revised Julian calendar (which is used by churches on the "New Calendar").
Saint George is not listed in the Synaxaristes. His memory is recorded in Lavreotic Codex E 152 pp. 367a. He is remembered as a Bishop of the Church of Christ in the period of the heretical Monotheletes in the 7th century, and he endured many trials by these Scythians (Greek: Σκύθες) for his commitment to the Orthodox Faith and piety.
A Gallo-Roman who at the age of thirty-five went to live as a hermit in the Jura mountains, where he was followed by his brother St Lupicinus. Many disciples soon gathered round the two brothers, who then founded the monasteries of Condat (later known as Saint-Oyend) and Leuconne, over which they ruled together, and the convent of La Beaume (later called St-Romain-de-la-Roche) where their sister was abbess.
"In the territory of Lyons, on Mount Jura, the demise of St. Romanus, abbot, who was the first to lead the eremitical life there. His reputation for virtues and miracles brought under his guidance numerous monks."[8]
Born in England of a noble Danish family, he was the nephew of St Oda of Canterbury. He went to Fleury in France to learn from monastic life and later became Bishop of Worcester (961), identifying himself with St Dunstan and St Ethelwold in their efforts to revive monastic life in England. St Oswald founded monasteries at Ramsey and at Worcester. In 972 he became Archbishop of York. He repose on his knees after washing the feet of twelve poor people, as was his daily practice.
The Roman Martyrology. Transl. by the Archbishop of Baltimore. Last Edition, According to the Copy Printed at Rome in 1914. Revised Edition, with the Imprimatur of His Eminence Cardinal Gibbons. Baltimore: John Murphy Company, 1916. p.61.
Rev. Sabine Baring-Gould (M.A.). "S. Proterius, M. Patr. of Alexandria. (A.D. 457.)." In: The Lives of the Saints. Volume the Second: February. London: John C. Nimmo, 1897. pp.451-452.
Rev. Sabine Baring-Gould (M.A.). "S. Romanus, Ab. of Condate. (A.D. 460.)." In: The Lives of the Saints. Volume the Second: February. London: John C. Nimmo, 1897. pp.452-454.
Rev. Sabine Baring-Gould (M.A.). "S. Oswald, Archb. of York. (A.D. 992.)." In: The Lives of the Saints. Volume the Second: February. London: John C. Nimmo, 1897. pp.455-456.
The Autonomous Orthodox Metropolia of Western Europe and the Americas. St. Hilarion Calendar of Saints for the year of our Lord 2004. St. Hilarion Press (Austin, TX). p.18.
February 28. Latin Saints of the Orthodox Patriarchate of Rome.
The Roman Martyrology. Transl. by the Archbishop of Baltimore. Last Edition, According to the Copy Printed at Rome in 1914. Revised Edition, with the Imprimatur of His Eminence Cardinal Gibbons. Baltimore: John Murphy Company, 1916. p.61.
(in Greek) Συναξαριστής. 28 Φεβρουαρίου. Ecclesia.gr. (H Εκκλησια τησ Ελλαδοσ).
Russian Sources
(in Russian)13 марта (28 февраля). Православная Энциклопедия под редакцией Патриарха Московского и всея Руси Кирилла (электронная версия). (Orthodox Encyclopedia - Pravenc.ru).