New Year's day in Sweden in January 1st according to the Gregorian calendar and celebrates the first day of the New Year.
Celebration\ Observance
People will spend the evening before enjoying food and drink with family and friends and some will attend firework shows. New Year's Day is also spent relaxing and time with family.
History
The Gregorian calendar was introduced by Pope Gregory XIII back in 1582, which puts January 1st as the very first day of each calendar year. Most of the world has adopted the Gregorian calendar but many countries still have their own calendar systems which puts their New Year's Day on a different date.