Wikipedia gives 3 dates for January being the first month, either (approx) 700, ...

		pbhjpbhj 6 days ago \| parent \| context \| favorite \| on: A Fast 64-Bit Date Algorithm (30–40% faster by cou... Wikipedia gives 3 dates for January being the first month, either (approx) 700, 450, 150 BCE. It's fair to say January was the first month of the Roman calendar; despite it having formerly been March.