It’s time to grab your purple poncho, hop in your Delorean, head to Gotham City and get ready to rock out.

The American Film Institute of Silver Spring on Friday starts its annual Silver Screens weekly series of outdoor movies in Veterans Plaza, with four popular movies that together have racked up more than $850 million in worldwide ticket sales.

But the Friday screenings are all free — no tickets needed.

“Thanks to the generosity of our own American Film Institute, Silver Screens is a great way for families to get together and enjoy some fun movies,” said County Councilmember Tom Hucker, who helped launch the series last year.

The screenings start at 8 p.m., rain or shine, in Veterans Plaza, 1 Veterans Place, in downtown Silver Spring.  Moviegoers are invited to bring their own seats.

Here’s this summer’s lineup:

  • Aug. 11: “Back to the Future Part II” (1989), starring Michael J. Fox, Christopher Lloyd and Elisabeth Shue.
  • Aug. 18: “Lego the Batman Movie” (2017), an animated feature with the voices of Will Arnett, Rosario Dawson, Zach Galifianakis and Conan O’Brien.
  • Aug. 25: “Purple Rain” (1984). Yes, it’s been 33 years since this film starring Prince and its Oscar-winning score was released.
  • Sept. 1: “School of Rock” (2003), with the irrepressible Jack Black.