Social media will be a big component of a new program announced by Disney Wednesday in which the company's parks in California and Florida will feature weekly surprise themes and events.

The “Limited Time Magic” program will include impromptu concerts, dance parties, colored lighting, character meet-and-greets, new menu and merchandise items and other events at Disney World and Disneyland.

Disney will use Twitter, blogs, websites and other online activity to let park visitors know what's happening. Guests might also be asked to vote on which characters they’d like to see or be sent on scavenger hunts with hints to figure out what's new or different.

“It's a fun, lighthearted, new way to get people engaged,” Leslie Ferraro, executive vice president of global marketing and sales for Walt Disney Parks and Resorts, said at a news conference in Manhattan.

Disney erected a 25-foot-tall castle made of ice in Times Square to symbolize the fleeting nature of the weekly surprises, and water ran down the turrets as the ice melted Wednesday morning. Blase New Yorkers hurried past without giving it a second glance but some fans and tourists donned mouse ears and took pictures.

Each “Limited Time Magic” theme will last a week. Plans include celebrations of July Fourth, “Pirate Week,” 3-D chalk art, “Long Lost Friends Week” featuring lesser-known Disney characters. A Valentine's Day celebration will feature pink and red lighting on Disney castles and romantic candlelit dinners in park restaurants.