Nona’s name day is August 5, the feast of Nonna the Righteous.
Churches that follow the Old (Julian) Calendar keep the same feast on August 18 of the civil calendar. See everything commemorated on August 5.
The saint behind the name
Nonna the Righteous
August 5, Holy Woman, Νόννα
Saint Nonna was the wife of Gregory of Nazianzus the Elder and the mother of Saint Gregory the Theologian, Saint Caesarius and Saint Gorgonia. Raised a Christian, she brought her husband to the faith and raised her children in piety.
Also celebrating on August 5
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.