Haris’s name day is February 10, the feast of Charalambos.
Churches that follow the Old (Julian) Calendar keep the same feast on February 23 of the civil calendar. See everything commemorated on February 10.
The saint behind the name

Charalambos
February 10, Martyr, Χαράλαμπος
St. Charalambos was a priest of Magnesia in Asia Minor who suffered martyrdom in extreme old age, according to tradition at the age of 113, during the persecutions of the early third century. Refusing to sacrifice to idols, he endured torture with such serenity that many who witnessed his suffering came to believe in Christ.
Name days: Charalampos, Babis, Haralambos, Harambos, Charalambos, Haralampos, Haris, Charis, Lambis, Harry, Charalambia, Haralambia, Haroula, Charoula
Also celebrating on February 10
These names share the feast, many of them other forms of the same name:
Charalampos, Babis, Haralambos, Harambos, Charalambos, Haralampos, Charis, Lambis, Harry, Charalambia, Haralambia, Haroula, Charoula
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.