Hiya Amber,
Thank you so much for stopping by planDisney with your dining question! Oh boy, how exciting that you’ll be attending  
Jollywood Nights at Disney’s Hollywood Studios! You’re in for such a glamorous evening—complete with dazzling décor, jazzy holiday tunes, and beloved Disney characters dressed to the nines for a night of Hollywood-style merriment. It’s one of my favorite ways to experience the holidays at Walt Disney World!
Now, let’s jump right into your question. The good news is that 
Jollywood Nights ticket holders can enter 
Hollywood Studios as early as 5:30 p.m. on the valid date of their ticket. That gives you a few extra hours to soak in the decor and grab a bite to eat before the party officially begins! Unfortunately, Guests will not be admitted earlier than 5:30 p.m. unless they have a separate valid theme park ticket (such as a Park Hopper, day ticket, or Annual Pass) that they choose to use that day.
If you’ve got your heart set on dining at 
Sci-Fi Dine-In Theater Restaurant, I highly recommend keeping an eye on your My Disney Experience app. Reservations often pop up closer to your visit as Guests adjust their plans—so don’t lose hope! I’ve had great luck snagging last-minute spots just a few days before my trip.
Another fun dining option right inside Hollywood Studios is 
Roundup Rodeo BBQ in Toy Story Land. It’s a rootin’-tootin’ good time with family-style dining, great flavors, and plenty of playful charm—Woody and the gang sure know how to throw a meal fit for a cowboy (or cowgirl)! This is my husband’s absolute favorite place to dine. 
Amber, I hope this helps you plan the perfect start to your Jollywood Nights adventure. If you have any additional questions, feel free to visit us again. 
See ya real soon,
Christina