I was also taught this. I wonder if it has something to do with this, from the article: > On Sosigenes' advice, Caesar added another two never-before-seen mon

I was also taught this. I wonder if it has something to do with this, from the article: > On Sosigenes' advice, Caesar added another two never-before-seen months to the year 46BC, one of 33 days and one 34, to bring the calendar in line with the Sun. The additions made the year the longest in history at 445 days long, with 15 months. The two additional months were a one-time-only thing for that year, but I can see wires getting crossed and having that be a thing that was repeated for a while. July and August were never added, though, simply renamed.