Disney parks started Fourth of July festivities three days before the actual holiday.

Nearby, Knott's will offer a fireworks show on the Fourth, and will offer free admission to veterans July 2-6.

On Sunday, Disneyland and Disney California Adventure launched their special entertainment features created for Independence Day. Fourth of July is one of the busiest holidays at the Disneyland Resort.

For the second year, a patriotic segment precludes the "World of Color" light-and-water display at Disney California Adventure. It includes scenes of national landmarks on spray screens, patriotic music and pyrotechnics. The "World of Color" addition runs at 9 and 10:15 p.m. Sunday through Wednesday.

Across the esplanade at Disneyland, a unique fireworks show, "Disney's Celebrate America! A Fourth of July Concert in the Sky," appears 9:30 p.m. Sunday through Wednesday.

The show was created in 2008. Until then, extra fireworks set to patriotic music ran at the end of the regular show on Fourth of July.

On the evening of July 4, the 3rd Marine Aircraft Wing Band will perform at several locations at Disneyland.

Knott's Berry Farm and Soak City will offer free entry to all active and retired military personnel (with ID) from July 2 through 6. Up to six family members can also get discounted tickets for $32.99 for Knott's (normally $57.99) or $27.99 for Soak City, (regularly $32.99). The offer is good for Knott's Soak City parks in Buena Park, Chula Vista, and Palm Springs.

On the Fourth, Knott's will hold its annual fireworks display, at 10 p.m.