Thirty-first

It's valid until March thirty-first, nineteen-ninety-seven.

The year starts on the first of January and ends on the thirty-first of December.

What is the thirty-first of December called?

My season ticket expires on March thirty-first.

The thirty-first of March fell on a Monday.

The japanese fiscal year goes from the first of April to the thirty-first of March the following year.

The answer appears on the thirty-first page of the book.

She finished thirty-first in the race.

A thirty-first of 620 is 20.