Athanassia’s name day is April 18, the feast of Athanasia of Aegina.
Churches that follow the Old (Julian) Calendar keep the same feast on May 1 of the civil calendar. See everything commemorated on April 18.
The saint behind the name
Athanasia of Aegina
April 18, Holy Woman, Αθανασία η εξ Αιγίνης
Athanasia was born on the island of Aegina in the ninth century and was twice married, the second time to a man who himself later became a monk. Freed to follow her heart's desire, she founded a convent on the island and was made its abbess.
Name days: Athanasia, Athanassia, Nasia, Athanasoula
Also celebrating on April 18
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.