Every sixth day of the month, we go on a picnic as a family.

I will hold my birthday party on the fourth day of the month.

Our new project will start on the third day of the month.

I will hold my birthday party on the tenth day of the month.

There is a test in two days.

He was studying all day.

Linear programming is a part of operations research and is used to find the optimal solution.

Paying the urban planning tax is a citizen's duty.

The United Nations Environment Programme is providing solutions to global environmental problems.

My mother carefully keeps the brush made with my fetal hair as a birth commemoration.