May 4, which is Sunday, marks the annual observance of Star Wars Day. It's celebrated on May 4 because of a certain line of dialogue from the films.

Here's why May the 4th is celebrated as Star Wars Day across the galaxy Beginning of dialog window. Escape will cancel and close the window.

Disney is marking the day with the launch of new Star Wars merchandise, ranging from lightsaber sets to jewelry, as well as a new series.

It didn't begin a long time ago or in a galaxy far far away, but every May 4 it feels like images, memes and promotional deals involving "Star Wars" have an inescapable gravity.

It didn't begin a long time ago or in a galaxy far far away, but every May 4 it feels like images, memes and promotional deals involving "Star Wars" have an inescapable gravity.

It didn't begin a long time ago or in a galaxy far far away, but every May 4 it feels like images, memes and promotional deals involving "Star Wars" have an inescapable gravity.

It didn't begin a long time ago or in a galaxy far far away, but every May 4 it feels like images, memes and promotional deals involving "Star Wars" have an inescapable gravity.

May 4 — or May the 4th, as fans say — has evolved over the years into Star Wars Day, an informal holiday celebrating the space epic and its surrounding franchise.