Why is December called the tenth month when it's actually the twelfth?

December means the tenth month, November the ninth, October the eighth and September the seventh, but none of them actually come at that point in our year. Whay has the Roman calendar created this oddity?

[@dominusnoster1805]

Hello mr goldsworthy, I really enjoyed your books! They straddle a very fine line between academic and popular, and I wish more history writers were like you. Merry Christmas from India!

[@RupertMarsh]

Very interesting - I thought I knew the answer to this question, but it turns out I was wrong! I shall now proceed to astound my friends and bore my enemies :)

[@angelacross2216]

Thank you.

[@anneneill5009]

We’re very spoiled to have had any videos in the lead-up to Xmas. Very grateful to AG for having taken the time. Looking forward to 2025’s offerings.

[@PrincipledUncertainty]

To my great delight, I just received The Eagle and The Lion for Christmas from my daughter. A perfect gift, as I spent last night wrapping presents while listening to Dr Goldsworthy talk to ToldInStone about this very book. I must have been a good boy this year.

[@alanpennie8013]

Props to Dionysius Exiguus for inventing *the common era*.

[@Unreliablecaptionbot]

Thank you for another video, I learn so much with each one. Have a great Christmas and new year!

[@jannarkiewicz633]

I am a software engineer. I had to write code for dates/times based on cultures. I knew a lot of this :-) but I always learn from Dr. Goldsworthy

[@gcazzalini]

Would you ever consider doing a book signing??

[@migueljimenez4303]

Interesting

[@user-zp5pp2xg9m]

What do we know about Antoninus Pius and his reign