The March madness march of maddened marchers

The ides of March is here. Happy new year! Eh? Well, I occasionally wonder about the Gregorian calender that we use to manage our daily life. Often I come to the conclusion that there's a 2 month offset. I know most of the month names are basically Roman names, but when I try to associate them with numbers, that's when the whole 2 month offset comes in place. Look at October. Tenth month of the year, but it has Octo in it. I know it's probably referring to Octavius, but if you think about it from words like Octagon, Octopuss, etc. Octo means 8, but October is the 10th month of the year. Then there's December, the 12 month of the year. However, the Dec, if I'm not mistaken comes from Decimal. 10. To decimate in groups of 10s. Etc. Also ever wondered why February only has 28 or 29 days in the year? That's because it's meant to be the end of the whole yearly cycle, and is basically filled with whatever days were left over in the division of the days in the year. So when and where did we offset the whole year so that it ended on December and begins in January? Well, that was just a fleeting thought.