Yeah, I’m aware of the origin an evolution of the term ‘Blue Moon.’ For the purpose of this question, I’m referring to two full Moons in a calendar month.
According to the wiki on Blue Moons, all of the ones between 2009 and 2021 have been in 31-day months. When was the last and next time it will be in a 30-day month?
(I think I need a hobby.)