May 5, 2017
When you mess with the bull, you’ll get the horns.
I picked this idiom because it’s May and I have a little bit of an interest in astrology. (Although I heard we could be off with our calendar. There may be even more constellations we chose not to include in our twelve-month calendar.)
Anyway, if you were born between April 20 and May 20, you are a Taurus, which is the bull.
Now, this was a rather hard idiom to research. There is not a lot to suggest where or when this saying developed, although I have a common idea.