Hello, Tina!
Great question!
Take a look at the
calendar page for Disney's Hollywood Studios for the month of June; you'll see that on both 6/21/12 and 6/23/12, Fantasmic! is offered at 9 p.m.
I took a look at Walt Disney World's online dining reservation site, to view for myself that four times you see there, and noticed that those times seem to reflect the various times that Fantasmic may be offered, depending on the season. If you click on the number of Guests dining that night, and ignore the time on that first page, you'll be taken to another page which includes up to three restaurants with available seating for the day on which you'd like to see Fantasmic. If multiple reservation times are available, those will appear next to each restaurant name, too. Under "You Searched For," you'll see the time that Fantasmic is offered on that day. (At that point in your search, even the reservation site will specify the time that Fantasmic if offered for your particular date.)
The Fantasmic! Dining Experience is such a wonderful opportunity to not only enjoy a really lovely meal, but also to gain access to a designated seating area for viewing this great show. (We LOVE Mama Melrose's Ristorante Italiano!) I'd still suggest that you arrive at Fantasmic an hour prior to the show starting, though, so plan your dinner reservation and other attraction-hopping accordingly. (You'll love the pre-show entertainment, too, which should start about 1/2 hour prior to showtime.)
I hope this clarifies things for you! Please be sure to send more questions as you think of them! I love to help!