Hey there, Jeannette, and welcome to planDisney!
Being an Arizonan myself, I was so jealous of the Disneyland Resort Grad Nites when I graduated high school - they look like such fun!
I've had the chance to answer a few questions this year similar to yours and I've found the two best places to look are the
Disneyland Resort Grad Nite overview page on Disneycampus.com and the
Daily Events Schedule on the Disneyland Resort website.
It looks like you're arrive on June 8, so it looks like the only Grad Nite that you'll contend with will be the one held on June 9. Luckily, these events are held later at night in
Disney California Adventure Park, so the events calendar is showing that the park will close at 9:00 PM on this night, which is just one hour earlier than normal. Meanwhile,
Disneyland Park will remain open until 12:00 AM on June 8-10, so as long as you have the
Park Hopper option then you can switch back over and enjoy this park for another couple hours!
I do have to caveat here as well that park hours are subject to change at any time, so I would recommend downloading the
Disneyland mobile app if you haven't already. You can see all kinds of helpful information in here including park hours and even estimated ride wait times when you're in the parks!
Thank you again for your question, Jeannette! I hope you have a phenomenal trip to the Disneyland Resort. Feel free to come back and see us with any follow-up questions you think of - we'd love to help!
Have a Magical Day,
Greg