Translation of "31st" in Japanese

On December 31st, he says, "I'm done."

大晦日に「止めた」と言い

I was born on the 31st of May in 1940.

私は１９４０年５月３１日に生まれた。

Let me remind you again that March 31st is the due date.

念のためにもう一度申しますが、締め切りは３月３１日です。

According to the terms of the contract, your payment was due on May 31st.

契約条件によれば、お支払いの期限は５月３１日でした。

- My season ticket expires on March 31.
- My season ticket expires on March 31st.
- My season ticket expires on March thirty-first.

- 私の定期券は３月３１日で期限が切れる。
- ３月いっぱいで定期が切れる。