Holy Martyr Theonas, the magician converted by the Hieromartyr Theopemptos.
St. Theonas was a sorcerer who, tradition relates, was sent to poison the Hieromartyr Theopemptos of Nicomedia during the persecution of Diocletian. Seeing the bishop unharmed, he believed in Christ and was baptized.
He was martyred together with Theopemptos, and the two are commemorated on January 5.
Feast day
On the New Calendar, Theonas the Martyr is commemorated on January 5. Churches on the Old (Julian) Calendar keep the feast on January 18 of the civil calendar.
Who celebrates a name day
People with these names keep their name day on this feast:
Also commemorated on January 5

Synkletike of Alexandria
Holy Woman, Συγκλητική
Venerable Synkletike, mother of women's monasticism in Egypt.
Name days: Synkletike, Synkletiki, Syncletica, Sygklitiki
Romanos of Karpenisi
Martyr, Ρωμανός ο Νέος
New Monk-Martyr Romanos, martyred in Constantinople in the seventeenth century.
Phosterios the Hermit
Venerable, Φωστήριος
Venerable Phosterios, a hermit who shone in the ascetic life.
Gregory of Akrita
Venerable, Γρηγόριος ο εν Ακρίτα
Venerable Gregory of Akrita, a monk of Crete and Constantinople.