September (Roman month) September (Roman month) September (from Latin "septem", "seven") or mensis September was originally the seventh of ten months on the ancient Roman calendar that began with March ("mensis Martius", "Mars' month"). It had 29 days. After the reforms that resulted in a 12-month year, September became the ninth month, but retained its name. September followed what was originally Sextilis, the "sixth" month, renamed "Augustus" in honor of the first Roman emperor, and preceded October, the "eighth" month that like September retained its numerical name contrary to its position on the calendar. A day was added to September in the mid-40s
Intercalary month (Egypt) and "epagomenal days" derive from Latin ' ("proclaimed between") and Greek "epagómenoi" () or "epagómenai" (, "brought in" or "added on"), Latinized as '. The period is also sometimes known as the "monthless days". In ancient Egypt, the period was known as the "Five Days upon the Year" (), the "Five Days" (') or "Those upon the Year" ('), the last of which is transliterated as . Parker also proposed that in some cases the intercalary month was known by the name Thoth ("") after the festival that gave its name to the following month. In modern Egypt, the period