That’s also why the months are numbered wrong. If you know Latin, or at least one of the romance languages that derived from Latin, then "Septem"ber should be the 7th month, "Octo"ber should be the 8th month, "Novem"ber should be the ninth month, and "Decem"ber should be the 10th month. But that’s not how it works today, as we no longer count March as the first month of the year.
That’s also why the months are numbered wrong. If you know Latin, or at least one of the romance languages that derived from Latin, then "Septem"ber should be the 7th month, "Octo"ber should be the 8th month, "Novem"ber should be the ninth month, and "Decem"ber should be the 10th month. But that’s not how it works today, as we no longer count March as the first month of the year.