Harry Potter might be known as the "Boy Who Lived," but over the weekend the character turned 36 years old. HP author J.K. Rowling also celebrated a birthday on July 31, since the writer shares a birthday with her iconic character.Online, fans celebrated Potter's birthday in a big way. The day was especially notable because July 31 was the release date for Harry Potter and the Cursed Child, the stage play written by Rowling, Jack Thorne, and John Tiffany. The play follows Harry's son Albus at Hogwarts, 19 years after the seventh book Deathly Hallows finished.Potter fans celebrated Harry's birthday with the hashtag #HappyBirthdayHarry