Right, I've realized that I sometimes happen to mention some of these in my confused writings. When trying to mention some of these I've realized that translating them doesn't feel all that right. So, this is the idea: if I explain them a bit here, in my usual to-the-point-consice style I can just link them here and everyone will be happy and just a teensy bit more educated. Wonderful, isn't it? Maybe not, but here we go anyway, in order of appearance ...
Valborgsmässoafton
Don't think this one has much of a correspondence in more English parts of the world, my dictionary suggests the German-sounding name Walpurgis night. Does it say everything to an English reader? Anyway, Valborgsmässoafton is the last night of April and it's when you celebrate the coming of May, spring and generally brighter and more pleasant days. People gather around big fires, think the original excuse is to keep away bad spirits, and sing spring songs.