Malachy’s name day is January 3, the feast of Malachi the Prophet.
Churches that follow the Old (Julian) Calendar keep the same feast on January 16 of the civil calendar. See everything commemorated on January 3.
The saint behind the name
Malachi the Prophet
January 3, Prophet, Μαλαχίας
The Holy Prophet Malachi is the last of the twelve minor prophets of the Old Testament. His name means messenger of the Lord, and his book, written after the return from the Babylonian captivity, calls the priests and people back to faithful worship.
Also celebrating on January 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.