New martyr
New Hieromartyr Thaddeus, Archbishop of Tver († 1937)
In Russian: Сщмч. Фаддея, архиепископа Тверского (1937)
In Church Slavonic: Ст҃а́гѡ сщ҃енномч҃ника ѳадде́а, а҆рхїепі́скопа тферска́гѡ (1937)
Feast days
2026
Old calendar
- (18 December on the Old calendar), repose
New calendar
- , repose
2027
Old calendar
- (18 December on the Old calendar), repose
New calendar
- , repose
Also commemorated on 31 December 2026
- Martyr Sebastian at Rome with his companions: Martyrs Nicostratus, his wife Zoe, Castorius, Tranquillinus the Presbyter and his sons the Deacons Marcellinus and Mark, Claudius, his son Symphorian and brother Victorinus, Tiburtius and Castulus († c. 287)
- Мч. Виктора (1936)
- Сщмчч. Николая, архиеп. Великоустюжского, Илии, Иоанна, Владимира и Николая пресвитеров (1937)
- Сщмч. Сергия диакона и мц. Веры (1942)
- Holy Hierarch Modestus, Archbishop of Jerusalem († c. 633-634)
- Venerable Florus, Bishop of Amis
- Venerable Michael Singelos, the Confessor
- Venerable Sebastian of Poshekhonye († c. 1500)
- Righteous Simeon, Wonderworker of Verkhotursk († 1694)