Christmas Eve is the day before Christmas Day, which is observed around the world as the festival commemorating the birth of Jesus. It is celebrated on December 24th every year. Christmas Eve is widely observed as a full or partial holiday in anticipation of Christmas Day, and together, both days are considered one of the most culturally significant celebrations in Christendom and Western society.

In the United States, Christmas Eve is not usually an official federal holiday, but it is a partial day off or a full day off in some states. It is a state holiday in Kentucky, Michigan, North Carolina, Oklahoma, South Carolina, Texas, and Wisconsin. Most schools and other educational institutions throughout the U.S. are usually closed on December 24th, and many organizations will open as usual, but some may close earlier or offer reduced services.

Christmas Eve is celebrated in different ways around the world, varying by country and region. Elements common to many areas of the world include the attendance of special religious observances such as a midnight Mass or Vespers and the giving and receiving of presents. In some cultures, presents are exchanged and opened on the night of Christmas Eve. Many homes have their Christmas trees lit up, mistletoes hung, and other Christmas decorations, such as holly and ivy, at this time of the year.

In conclusion, Christmas Eve is celebrated on December 24th every year and is the day before Christmas Day. It is widely observed as a full or partial holiday in anticipation of Christmas Day, and it is celebrated in different ways around the world, varying by country and region.