My question involves employment and labor law for the state of: Missouri

I am required to give my boss 2 weeks notice to resign. I accepted another job that starts January 4th. Due to the holiday season and respect for my boss, I decided to tell him on December 2 about the other job and have him my resignation letter. However, I said that I want my two weeks to start December 16 so I can work up until I start my other job. It states December 16th in my resignation letter.

Although he was okay with it at first, he then said he wants me to just leave on the 15th of December and start my two weeks right away?

Do I have any rights to what my resignation letter said due to the dates? Since I told him early, he doesn't want me to work that long to save him 2 weeks pay.

What are my options, if any? Any advice would be great. Thank you.