Name days
Finns celebrate their name days according to their given name on the date given by the calendar published by the Almanac Office of the University of Helsinki.
Every day except New Year's Day, Christmas Day and February 29 is a name day. For each day there are names in both Finnish and Swedish.
Many traditional beliefs attach to various name days, especially involving the weather and the appropriate times to perform seasonal agricultural tasks such as planting some particular crop. For example there is a saying that "Jaakko (James) casts a cold rock into the water", meaning that on Jaakko's day, the 25th of July, the waters start getting colder.
It is customary to congratulate, send a card or give a small gift on someone's nameday.
The Swedish namedays differ in Finland and Sweden
Here is a list of the Swedish names and dates (in Finland)
Here is a list of the Finnish names and dates (in Finland)
Here is a list of the Swedish names and dates (in Sweden)
Find out what your name means at Historiska Museet's historical database.