Agapius’s name day is March 15, the feast of Agapios.
Churches that follow the Old (Julian) Calendar keep the same feast on March 28 of the civil calendar. See everything commemorated on March 15.
The saint behind the name
Agapios
March 15, Martyr, Αγάπιος
St. Agapios was a martyr who suffered at Caesarea in Palestine during the great persecutions at the beginning of the fourth century. Together with several companions, he confessed Christ before the governor and refused every inducement to sacrifice to the idols, and so was put to death for the faith.
Also celebrating on March 15
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.