According to daysoftheyear.com, "This first World Tennis Day was celebrated in 2013 when the event was established through the efforts of the International Tennis Federation (ITF), which is the main governing body of the game. Stargames was also involved in promoting the launch of the day.
The inaugural World Tennis Day started as a way to celebrate the 100th anniversary of the ITF and it has been an annual event since that time. This day acts as a perfect opportunity to bring focus to the sport through various special events as well as media coverage that shines a spotlight on tennis!"