Today is a big day in Sweden. Valborgsmässoafton, originally from the german Walpurgistag( 1st of May). So the eve before this day, is many times connected to witches and therefore the fires and fireworks are common.
In Sweden it is a big day for welcoming the Spring with singing and celebrating. It is probably, together with midsummer, the biggest holiday if counting the amount of alcohol cunsumed. 🙂