A name day (also known as feast day) is a tradition in many countries in Europe of celebrating a day based on an individual's given name. The custom originated with the Catholic and Orthodox calendar of saints, where believers, named after a particular saint, would celebrate that saint's name day. In many countries, however, there is no longer any explicit connection to Christianity.
The celebration of name days differ greatly between countries. There are many countries that consider name days as significant as their birthdays, while there are some that still barely recognize the tradition. With those countries that still celebrate it, each year's calendar is generally printed with the names to be celebrated. The names differ greatly also. Some countries have names of Saints, while others have selected specific names for each calendar day. In some cultures, a name can appear more than once. In this situation, the individual celebrates the name day closest to his/her birthday.
Find your name day: source : NameDayCalendar
*According to the Greek Orthodox Calendar, each day of the year is dedicated to the memory of a saint or martyr; usually more than one on the same day. Each saint has his special feast day; on that day Greeks also celebrate their name days, which is the feast day of the saint after which they are named.