Why Is October The Tenth Month?
October is the tenth month today thanks to Emperor Julius Caesar who changed the calendar from a lunar basis to one with an emphasis on the solar year.
The meaning of October comes from the Latin word Octo meaning eight. The old Roman calendar started in March, so October was the eighth month. When the Roman senate changed the calendar in 153 BCE, the new year started in January, and October became the tenth month.
The Roman Calendar
The Roman Calendar was used from approximately 509 BCE to 27 BCE and was based on lunar (moon) cycles. At that time, the Romans believed there were only 10 months and that the first month began in March. The Octo in October means eight, thus the eighth month from March.