7 a.m Symbio Fitness, a new gym in South Beach, hosts an open house until 7 p.m. Guests can try classes, receive a free one-day pass, take a tour of the facilities and enter for a chance to win a free three-month membership. Symbio Fitness, 1815 Purdy Ave., Miami Beach; symbiofit.com.FASHION4 p.m.Super star DJ Armin van Buuren hosts the launch for his limited edition line of sneakers and apparel created exclusively for Quick Sports International. Rooftop at the Gansevoort, 2377 Collins Ave., Miami Beach; firstname.lastname@example.org.AFTER PARTY11 p.m. Wall hosts the official Masquerade Motel after show with Swedish House Mafia and many more. Sorry, tables only! Wall at W South Beach, 2201 Collins Ave., Miami Beach; RSVP@WallMiami.com.