It is observed annually on the Friday before the March Equinox or the northern hemisphere vernal equinox.
It is an annual event organized by the World Sleep Day Committee of the World Sleep Society.
The first World Sleep Day was held on 14 March 2008.
Theme of the year 2020 is 'Better Sleep, Better Life, Better Planet'.
About
The March equinox is known as the vernal equinox (spring equinox) in the Northern Hemisphere and as the autumnal equinox in the Southern.
The March equinox may be taken to mark the beginning of spring and the end of winter in the Northern Hemisphere but marks the beginning of autumn and the end of summer in the Southern Hemisphere.