I just realized that the last months of the calendar are remnants from the Roman calendar. The problem with this is that their names do not correlate with their position in the Gregorian calendar:
September/Septembris - 7th
October/Octobris - 8th
November/Novembris - 9th
December/Decembris - 10th
Why couldn't the gregorians keep the month placements? Wrong questions only