Star Wars Day is an informal commemorative day observed annually on May 4 to celebrate George Lucas' Star Wars media franchise. Observance of the day spread quickly through media and grassroots celebrations since the franchise began in 1977. Wikipedia
May 4, 2021 — That explains why you will be seeing "May the 4th Be With You," all over the internet today. May 4th has become known as Star Wars Day, an unofficial holiday that gets its origin from a line of dialogue in the first movie released in George Lucas' space saga, "Star Wars: A New Hope."
May 4, 2021 — The reason Star Wars fans chose May 4 is that the date resembles one of the most famous lines repeated throughout the film: “may the Force be with you,” which changes to: “May the Fourth be with you,” on this day every year.