Unfortunately like all good things, The Disneyland Resort does have to close the doors on its attractions for short periods of time. These closures allow the resort to perform regular maintenance and clean up the attractions. The off season is the time when most of the closures occur, so that way most are up and running when all the crowds are in the park. The yearly maintenance of a ride can take from a few weeks to a month or longer but most usually last for about 3 - 4 weeks. The dates officially released by Disney are very close estimates of the length of time, and rides usually close and open almost exactly on those dates. Sometimes they get done early and reopen the ride accordingly.
If they get behind schedule they will usually make note of the changes so Guests don't get upset. Guests who are planning to travel to the park on a date right around the opening or closing of a ride that really want it to be open when they make their trip should try contacting Disneyland Guest Relations at (714) 781-7290 to get the most up to date schedule. To help give Guests an idea of what attractions will be closed over the next few months, below is a list released by The Disneyland Resort detailing the upcoming and current attraction closures.
DISNEYLAND RESORT REFURBISHMENTS
Disneyland Refurbishments it's a small world 01/22/08 - 11/28/08
Haunted Mansion 09/08/08 - 09/25/08
Mark Twain Riverboat
11/03/08 - 11/05/08
French Market
09/02/08 - 09/19/08
Sailing Ship Columbia
09/02/08 - 10/25/08
Fantasmic!
09/02/08 - 11/06/08
Big Thunder Ranch
09/15/08 - 09/25/08
11/03/08 - 11/14/08
Jungle Cruise
10/20/08 - 10/22/08
Harbour Galley
09/02/08 - until further notice
Disney's California Adventure
Refurbishments Flik's Flyers
09/02/08 - 09/12/08
Burger Invasion
09/02/08 - Until Further Notice
Hyperion Theater
09/02/08 - Until Further Notice.
Sun Wheel
09/11/08 - 02/26/09
**All information subject to change without notice