My solution is longer because for some reason my brain thought part of it was having the workflow be able to translate the months for you (not writing out S=September, etc). I made this one harder for myself than it needed to be
I wanted to do this in a way to avoid a long formula, but in all honesty I need practice with expressions so I followed along with original solution. One thing I didn't get was why there were AND statements for months of Jan,Jun,Jul and Apr,Aug, but not for not May, only Mar. Seemed excessive and inconsistent.