A name day is a tradition in some countries in Europe, Latin America, Catholic and Orthodox Christian countries in general. It consists of celebrating a day of the year that is associated with one's given name. The celebration is similar to a birthday.
The custom originated with the Christian calendar of saints: believers named after a saint would celebrate that saint's feast day, or in the Eastern Orthodox tradition, the day of a saint's death. Name days have greater resonance in the Catholic and Orthodox parts of Europe—Protestant churches showing less veneration of saints. In many countries, however, name-day celebrations no longer have connection to explicitly Christian traditions.
The celebration of name days has been a tradition in Catholic and Orthodox countries since the Middle Ages, and has also continued in some measure in countries, such the Scandinavian countries, whose Protestant established church retains certain Catholic traditions. The name days originate in the list of holidays celebrated in commemoration of saints and martyrs of the church. For example, the name Karl or Carl is celebrated in Sweden on January 28, the anniversary of the death of Charlemagne (Charles magnus, i.e., "the great"). The church promoted celebration of name days (or rather saints' feast days) over birthdays, as the latter was seen as a pagan tradition.
Where name days occur an official list is held containing the current assignations of names to days. There are different lists for Finnish, Swedish, Sami, and other countries that celebrate namedays, though some names are celebrated on the same day in many countries. From the 18th century and onwards the list of name days has been modified in Sweden and Finland.