Modern box-office records set with an extra evening of screenings deserve an asterisk, some industry insiders say, much like records set by athletes who use performance-enhancing drugs.

WSJ: Hollywood Stretches Out Movie 'Openings'

Though most milongas do include an impressive invitational performance from professional dancers mid-way through the evening, the dance floor is open for improvisation the rest of the night.

BBC: The tango Buenos Aires tourists never see

Saturday evening also saw an anticipated 700 million people watch state television's annual TV gala, a variety performance show in which Celine Dion sang her theme tune from the movie Titanic.

BBC: Chinese Year of Snake celebrations in Asia