International Day for Biological Diversity is being celebrated on 22 May every year to increase awareness and understanding of the issues of biodiversity.
World Thyroid Day is being celebrated on May 25 to promote awareness and understanding of thyroid diseases, their symptoms, prevention, and treatments.
The International Day of Light is being celebrated on 16 May each year, the anniversary of the first successful operation of the laser in 1960 by physicist and engineer, Theodore Maiman.