As the Icelanders got introduced of Christianity in the year 1000 and old heathen feasts and celebrations were intertwined with the Christian ones. Now, they celebrate both the old and the news feasts. Like every other country, they celebrate their own carnival season on these three days.
Bolludagur (Cream Bun Day): The tradition is that the children make and decorate their own Bun Day paddles at school and use the paddles to spank their parents, a little bit odd right but a very playful and special day for the children.
Sprengidagur (Bursting Day): Families come together and serve salted meat on the table, usually lamb but occasionally horse meat with bean stew on the side. Practically this day is about eating your stomach full, as the old Christian custom was to fast during the coming season of Lent. However, it is not known anymore in Iceland to fast but the Bursting Day still remains as Icelanders do love food and nothing better but to have a full stomach!
Öskudagur (Ash Day): All the Icelandic schools are closed and the children get the day off to dress up in costumes and wander between shops and businesses to show their singing talent for a candy. The only way to earn candy is to sing songs, you can say that this is a bit of an Icelandic version of Halloween although Icelanders also celebrate Halloween like almost all other countries.