October (Roman month) October (Roman month) October (from Latin "octo", "eight") or mensis October was the eighth of ten months on the oldest Roman calendar. It had 31 days. October followed September (from "septem", "seven") and preceded November ("novem", "nine"). After the calendar reform that resulted in a 12-month year, October became the tenth month, but retained its numerical name, as did the other months from September through December. Some of the observances in October marked the close of the season for military campaigning and farming, which commenced in March ("Martius", "Mars' month"). October was under the guardianship "(tutela)" of Mars. The Romans
Gregorian calendar to globalization in the 20th century, the calendar has also been adopted by most non-"Western" countries for civil purposes. The calendar era carries the alternative secular name of "Common Era". The Gregorian calendar is a solar calendar with 12 months of 28–31 days each. A regular Gregorian year consists of 365 days, but in certain years known as leap years, a leap day is added to February. Gregorian years are identified by consecutive year numbers. A calendar date is fully specified by the year (numbered according to a calendar era, in this case "Anno Domini" or Common Era), the month