Wikipedia Day is observed worldwide on January 15, celebrating the launch of Wikipedia in 2001 by Jimmy Wales and Larry Sanger. The name "Wikipedia" was coined by Sanger, combining "wiki," meaning quick in Hawaiian, and "pedia," from encyclopedia. Initially launched in English, Wikipedia quickly expanded to multiple languages, with the English version remaining the largest. The day is marked by various local meetings and wiki-events, continuing a tradition that gained prominence with a significant global celebration in 2011. As one of the largest non-profit projects on the Internet, Wikipedia attracts about 500 million unique visitors each month and features 18 billion pages, highlighting its impact on information sharing. Additionally, January 15 is also the founding date of WikiHow, chosen to honor Wikipedia Day.