Hi Elsa,
Welcome to planDisney! I hope you're counting down the days until your magical visit later this month! Having a Disney adventure to look forward to can put a little pixie dust and magic into any ordinary day!
While multi-day tickets may be used on any date,
single-day tickets may have limitations as to when they may be used. There are
various tiers for tickets, and their cost will vary based on the time of the year and even the day of the week. The good news for you is that if you already purchased a ticket for September 25th, that ticket is valid on any day of the year as it is a Tier 5 ticket and allows you the most flexibility. If you're using a ticket that you previously purchased, though, it may need to be upgraded before you'll be able to use it on your preferred date. You'll be able to do that at a Disneyland Resort ticket booth or any Guest Relations location and will simply need to pay the difference between the ticket you currently have and the one to which you'd like to upgrade. Of course, please don't forget that
theme park reservations are also required for entrance into the theme parks!
Thanks so much for visiting us at planDisney, Elsa, and please let us know if we can help with anything else as you're thinking through the details of your visit. I hope you have a truly magical Disneyland Resort adventure later this month!
Missy