Makrine’s name day is July 19, the feast of Makrina the Elder.
Churches that follow the Old (Julian) Calendar keep the same feast on August 1 of the civil calendar. See everything commemorated on July 19.
The saint behind the name

Makrina the Elder
July 19, Holy Woman, Μακρίνα
St. Makrina belonged to the extraordinary Cappadocian family of saints that gave the Church St. Basil the Great and St. Gregory of Nyssa. A woman of deep piety and steadfast faith, she devoted herself to prayer and the ascetic life, and through her teaching and example the Orthodox faith was handed down within a household that produced some of the greatest fathers of the Church.
Also celebrating on July 19
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.