Here in the U.S., and in other places in the world such as Ireland, tomorrow, March 17th, is a popular holiday (or feast day) for St. Patrick, the patron saint of Ireland. People wear green, eat corned beef, drink green beer, and even (at times) dye rivers green.
Apparently some Finnish Americans living in Northern Minnesota got a bit jealous of all the fun Irish Americans had, and decided to celebrate their patron saint the day before St. Patty's Day. Unfortunately, there wasn't a convenient patron saint to honor, so the Minnesota folks made one up.
And so was born St. Urho, the legendary patron saint of Finland.
There really was a St. Patrick, although some of the stories told about him are surely fiction / legend. For example, the fact that there are no snakes in Ireland has more to do with the fact that Ireland is an island, like the snake-free islands of New Zealand and Iceland, than from the story that St. Patrick drove all the snakes out of Ireland. But the inventors of St. Urho were inspired by the snake-ridding legend to create a similar story for their hero: St. Urho was said to have saved the grape crop in Finland by chasing the grasshoppers out of ancient Finland by saying something like, “Grasshopper, grasshopper, get out of here.”
(Note that, although Ireland really does lack snakes, Finland still has grasshoppers. So St. Patrick drove away the snakes for all eternity, but St. Urho presumably just saved the one crop. It was a one-off miracle, I guess!)
St. Urho and his day have traditional colors, too—purple and green. Purple stands for the grapes, and green stands for the grasshoppers that were driven away and also for the vines. Oh, sorry, I should be more exact: today's colors are royal purple and Nile green.
St. Urho Day was created, not in ancient or medieval times, but in the 1950s. I'm not positive it's true that Finns and Finnish Americans celebrate the day by chanting St. Urho's anti-grasshopper charm while walking in procession, kicking and waving pitchforks to scare off grasshoppers. But I definitely believe that people celebrate by singing, dancing polkas, and drinking wine and grape juice. A traditional food for St. Urho Day is fish soup.
Also on this date: