The Truth About the Calendar-13 Months Not 12, 28 Days Not 30

Did you know there use to be 13 months in the calendar and that we are missing a month? Did you know that the new years was originally in Spring during the Spring Solstice and not in Winter? Did you know October was named after to Octa meaning eight in Latin, because it was the eighth month, not the tenth? Did you know there once was only 28-days in a month, which correlates to the cycles of the moon and to women's monthly cycles? Why was it changed and who benefits from it being changed? Why did Rome change the calendar?