International Day for the Preservation of the Ozone Layer commemorates the day in 1987 on which the Montreal Protocol on Substances that Deplete the Ozone Layer was signed - September 16. It was first celebrated in 1995 and provides an opportunity for states to devote the day to promote activities in accordance with the objectives of the Protocol and its amendments.

The ozone layer, a fragile shield of gas, protects the Earth from the harmful portion of the rays of the sun, thus, helping preserve life on the planet.