The thirty-first day is my birthday.

We have our wedding on the twenty-first day of the month.

We have our wedding on the twenty-third day of the month.

We celebrate our wedding anniversary on the twenty-fifth day of the month.

Our project is scheduled to be completed on the twenty-second day of the month.

Learning about the history of the Kōkyū jūni-shi is very interesting.

He has a wealth of knowledge about the zodiac.

The new project will start in seventy-five days.

He made a model of a regular dodecahedron.

He made a model of a regular icosahedron.