Voukoulas’s name day is February 6, the feast of Bukolos of Smyrna.
Churches that follow the Old (Julian) Calendar keep the same feast on February 19 of the civil calendar. See everything commemorated on February 6.
The saint behind the name

Bukolos of Smyrna
February 6, Hierarch, Βουκόλος
St. Bukolos was a disciple of St. John the Theologian, who consecrated him the first Bishop of Smyrna in Asia Minor. In the earliest days of the Church he shepherded his flock amid the surrounding paganism with gentleness and wisdom, bringing many to the faith of Christ.
Also celebrating on February 6
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.