Vonifatios’s name day is December 19, the feast of Boniface.
Churches that follow the Old (Julian) Calendar keep the same feast on January 1 of the civil calendar. See everything commemorated on December 19.
The saint behind the name

Boniface
December 19, Martyr, Βονιφάτιος
The holy martyr Boniface was a servant of a wealthy Roman woman, Aglais, in the early fourth century. Sent by her to the East to bring back relics of the martyrs, he watched the sufferings of the confessors at Tarsus, was pierced with compunction for his own careless life, and openly declared himself a Christian; he was tortured and beheaded, and his own relics were carried back to Rome, where Aglais received them and thereafter lived in repentance.
Name days: Vonifatios, Boniface
Also celebrating on December 19
These names share the feast, many of them other forms of the same name:
What to say on a name day
The Greek wish is Χρόνια Πολλά (Chronia Polla), “many years.” A call or a short message on the day is what people remember. See name day wishes you can send and what a name day is.