[ianburrell]

That happened later, well after January and February had been added. I think the twelve month Roman calendar was from pre-history so we don't know when or why it was done. July and August were Quintilis and Sextilis, five and six.

[asveikau]

Yeah, seems like I mixed my calendar history up. Reading this set me straight: https://en.m.wikipedia.org/wiki/Roman_calendar

Thanks for the reply, it led me to look into it deeper.