Greetings Savannah,
Thank you for making a magical stop here at the Disney Parks Moms Panel with your question. I hope you are having a Fantasmic day!
The Rock Your Disney Side Event was a fun celebration last year from 6:00 AM to 6:00 AM, May 23 to May 24, 2014. 24-hours of pure Disney magic always sounds like a not-to-be-forgotten time for the whole family. While inside the parks, all Guests were allowed to dress in costume to "Rock Your Disney Side" while Disney Princesses, Villains, Pirates, and more were out to play.
Unfortunately the schedule for this event in 2015 has not been released yet. Keep checking the Disneyland website and the Disney Parks Blog for magical updates.
I hope this helps and that you have a pixie-dusted time on your next visit. If you have any more questions, please
visit me here and let me know how I can help you plan your magical vacation.
Wishing you magic!
~ Lynette