On Christmas Eve Day in Greece, young people, carrying triangles, small drums, and harmonicas, go in groups from house to house, singing the kálanda (carols) abut the birth of Christ. (See "Kalanda Christouyennon" below) Before singing the children ask the traditional question, "Na ta poúne?" ("May we sing it for you?"). (The question is asked so that songs will not be sung at the house in mourning.) Some children carry small ships of cardboard, wood, or tin in honor of St. Basil who came to Greece by sea from his home in Caesarea to bring presents to the children. Decorated with the Greek flag and the word "Ella," the ships hold the sweets and money given to each caroler at the end of the kálanda. Sometimes the children are welcomed into the house for treats. In America, this is a popular activity for Greek school students.

Sweets
The most traditional Christmas cookies are the white, powdery kourabiéthes and the rich melomakárona. The cloves in the kourabiéthes represent the spices of the wise men.

Christmas Bread (Chirstopsomo)
Christmas bread (Christopsomo - pron. Christopsomo) or kouloúra tou Christoú (round bread of Christ) graces the Christmas table. It is usually a round loaf often made with the same ingredients as Ester bread. Nuts and dried fruits may be added. Some families attend church on Christmas Eve and return home for a meal that begins with the cutting of the Christopsomo by the head of the household. Others wait until a main meal on Christmas Day. The head of the house makes the sign of the cross on the bread with a knife while saying, "In the name of the Father, the Son, and the Holy Spirit, " and then cuts a piece for each person with a wish of "Kalá Christoúyena" ("Good Christmas") or "Chrónia pollá"  ("Many years"). (See recipe below)

In Cyprus, special bread and pastries covered with sesame seeds and a cross on top are prepared. For blessings on the house, one will be hung from the beam of a ceiling or maybe in front of the home ikonostási through Christmas or New Year's Day.

Greetings
Wish someone a Merry Christmas with "Kalá Christoúyena" ("Good Christmas") or "Chrónia pollá"  ("Many years") or "Ke tou chrónou" ("And to next year").

Gifts
Most Greek Americans exchange gifts on Christmas Eve or Christmas Day, not at New Year's as in Greece. Greek-American youngsters look to Santa Claus, not St. Basil, for their presents.

Name Day Celebrations
In Greece Christmas Day is a very popular time to hold open-house name day parties to honor persons with names such as Chris, Christos, Christine, Emmanuel, and Emmanuela. This is not widely done in the United States.

Kalikántzari Superstition
An old folk belief in Greece holds that mischievous goblins called kalikántzari appear during Dodecameron. The kalikantzari live beneath the surface of the earth and chop away at a large tree trunk, the foundation of the earth. With their chopping they attempt to destroy God's work. They almost succeed when they hear the noise created by the birth of Christ. They come to earth on December 25 to disrupt people's lives with pranks and tricks such as spilled milk, disappearing keys, and broken glass. It is common to blame mishaps this time of the year on the kalikántzari.

Fire, light, and holy water protect people from the kalikantzari.
On Christmas Eve some people in rural Greece light a fire to prevent them from coming down the chimney. This Christ log (skarkántzalos) burns until Epiphany. Sometimes large bonfires are built in the villages of Greece, and people carry a candle with them at night for protection. The little imps roam the earth until Epiphany when holy water cleans them away.

Excerpt from the book Greek Traditions and Customs