Diodoros’s name day is May 3, the feast of Diodoros and Rhodopianos.
Churches that follow the Old (Julian) Calendar keep the same feast on May 16 of the civil calendar. See everything commemorated on May 3.
The saint behind the name
Diodoros and Rhodopianos
May 3, Martyr, Διόδωρος και Ροδοπιανός
Diodoros and the deacon Rhodopianos preached Christ in the city of Aphrodisias in Caria during the persecution of Diocletian. Seized by the pagans of the city, they were stoned to death for their confession.
Also celebrating on May 3
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.