The last February 30th occurred in 1712, in Sweden. However, according to Tolkien, it happens every year, in the Shire.
That's because Tolkien was logical, and had no use for things that didn't make sense. Which is why I love his works.
And, FYI, France instituted a convoluted calendar that consisted of 100 minute hours, 100 second minutes, and something else that has escaped my logical thinking. One hundred hour work-weeks?
*sheesh* I'm thinking it's way past my bedtime.