Hi there, Cesar!
Welcome to planDisney and thanks for bringing your question to us! I'm excited for you to be planning a late summer visit to the Disneyland Resort. I love those long Southern California days and warm nights and I have fond memories of staying in the Parks until they closed at midnight as a child.
If you purchase a regular
Theme Park Ticket, you are free to cancel and re-book your reservations at will until the ticket's expiration date, which should not be for quite a while. So if you marked dates in July for your original plans, just head over to
Ticket and Reservation Details and click on "Make or Modify Park Reservations" to change them to another date in August. Just be aware of the
Tier system for One Day Tickets and that not all days might be eligible if you have a lower tier ticket. Also, multi-day tickets must be used within 13 days after its first use, so factor that into your plans as well. All Park Guests must have a ticket and a valid reservation for the day of their visit.
You're going to be visiting the Disneyland Resort during my favorite time of the year,
Halloween Season! The characters will be dressed in cute costumes and there'll be pumpkins decorating Main Street U.S.A. everywhere. Look for Haunted Mansion Holiday to be returning for the Season with a new
Grounds Expansion and Retail Shop!
Fun Fact: the infamous Hatbox Ghost in the Haunted Mansion was actually present when the attraction opened in 1969, but was removed after a short time. He finally made his triumphant return in 2015 and has been a fan favorite ever since, only recently having made his way to the Haunted Mansion in the Walt Disney World Resort.
Cesar, I hope that this was helpful and informative for you. Please come by again anytime you have another question because we'd love to hear from you. Until next time!
Wishing You a Great, Big, Beautiful Tomorrow!
-Al