Ninian’s name day is September 16, the feast of Ninian of Whithorn.
Churches that follow the Old (Julian) Calendar keep the same feast on September 29 of the civil calendar. See everything commemorated on September 16.
The saint behind the name
Ninian of Whithorn
September 16, Hierarch, Νινιανός
St. Ninian was a Briton of the fourth and fifth centuries who, tradition relates, studied in Rome and was sent as bishop to his people. He built a stone church at Whithorn in Galloway, called Candida Casa, and from it preached Christ to the southern Picts.
Name days: Ninian
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.