Every spring since 2011, a multigenerational assortment of Grateful Dead fans have gathered at theaters across the United States for their annual Meet-Up at the Movies. The trend will continue this year when thousands of Deadheads reconvene for a 40th anniversary screening of 1977’s the Grateful Dead Movie on Thursday, April 20, which may or may not double as a celebration of a different nature for many of them.

While most editions of Meet Up at the Movies have featured screenings of entire Grateful Dead shows, this year will take its cues from the inaugural event by showing the 1977 film. Directed by Jerry Garcia and acclaimed documentary filmmaker Leon Gast, The Grateful Dead Movie captures the iconic band—and their devoted followers—during a five-night run at San Francisco’s famed Winterland Ballroom in October 1974, just before their 1975 touring hiatus (the live album Steal Your Face was compiled from the same run of of shows). Grateful Dead favorites like “Truckin’,” “Eyes of the World,” “Sugar Magnolia,” “Playing in the Band,” “Morning Dew” and more all make appearances in the film.

However, The Grateful Dead Movie will not be the only thing on the agenda this Thursday. Fans will also be treated to an exclusive mini-documentary about one of the most beloved Dead shows of all time—their beloved May 8, 1977 concert at Cornell University’s Barton Hall—as that milestone is nearing its 40th anniversary as well.

Deadheads can be found in all corners of the globe, so it should come as no surprise that the New Orleans area will be hosting a few The Grateful Dead Movie screenings of its own on April 20. Participating theaters include the Theatres at Canal Place (New Orleans), the Westbank Palace 16 (Harvey) and the Elmwood Palace 20 (Elmwood). Showtime will be 7pm at all three theaters. Tickets are available here.