Welcome to planDisney, Erica!
I'm so glad that you were able to take advantage of the
California Resident ticket offer this year! It is definitely one of the best deals around! If you are unable to make it to the parks on September 5th as you have planned, you still have until September 30th to use the last day of your three-day ticket. I took a quick glance at the
theme park reservation calendar and it appears that there is still plenty of availability for the rest of the month! So I really hope you can plan one more visit before the end of the month. If not, unfortunately there are no refunds or credits given for the unused portion of your ticket.
September is an exciting time to the visit the Disneyland Resort as
Halloween Time kicks off today, September 3rd! This means that the parks are decked out with all sorts of fall decor, there are special Halloween treats to enjoy, the Haunted Mansion Holiday overlay is back, and you can experience the Halloween Screams nighttime spectacular. Your favorite characters are celebrating the season too as they are all dressed up in their Halloween costumes.
I hope this helps. Have a magical day!
-Linda