Ticket sales for Disney/Marvel's The Avengers surged internationally on May 1, the May Day holiday in many countries, raising expectations that the movie's worldwide gross will soar well past $500 million following this weekend's opening in North America, China and Russia. Domestically, the film is expected to open in 4,349 locations, with fewer than 1,000 showing it in 2D, thereby assuring it of premium pricing at most venues. IMAX reported that the movie will play in 275 IMAX theaters in the U.S. and an additional 176 overseas. Theaters are reportedly scrambling to add staff so that they can open it at midnight and slot in additional screenings in the late-night and morning hours on Saturday and Sunday. Several industry pundits are predicting that The Avengers will open domestically at around $155 million. That would make it the third-highest-grossing premiere ever, behind Harry Potter and the Deathly Hallows Part 2 , which raked in $169.19 million last year and The Dark Knight , which collected $158.41 million in 2008.