National DNA Day is a holiday celebrated on April 25th. It commemorates the day in 1953 when James Watson, Francis Crick, Maurice Wilkins, Rosalind Franklin, and colleagues published papers in the journal ‘Nature’ on the structure of DNA.
In the United States, DNA Day was first celebrated on 25th April 2003 by proclamation of both the Senate and the House of Representatives. However they only declared a one-time celebration, not an annual holiday. Every year from 2003 onward, annual DNA Day celebrations have been organised by the National Human Genome Research Institute (NHGRI) starting as early as April 23 in 2010, April 15th in 2011 and 20th April in 2012.
April 25th has since been declared ‘International DNA Day’ and the ‘World DNA Day’ by several groups.
Taken from Wikipedia page ‘DNA Day’
