Tennis Opening Day celebrates the start of the summer tennis-playing season by encouraging folks to get out and play and share photos and videos of them doing so by social media in order to win prizes. Additionally, free tennis instruction for all ages and abilities will be offered at sites across the Chicago area: Rainbow Beach and Humboldt Park in the City of Chicago, Nike Park in Naperville, James Park in Evanston, Community Playfields in Wilmette, Flossmoor Park in Homewood Flossmoor, and Butterfield Park District Tennis and Pickleball Courts. The day is made possible through a presenting sponsorship from Xfinity.