Blue Moon Myth
The lunar cycle, from an astronomical perspective, the Moon’s orbit is 28.5 days. Divided into an Earth orbit of 265 days? That gives us 12.8 “lunar cycles” in the same time we’ve got 12 months, or, in my world, 12 signs.
So, depending on the physics and described by the dynamic, there should be about one Blue Moon in a year. Maybe more, sort of depends on the lunar cycles.
1946 — this is a recent name, recent “invention.”
Make of it what you will.