I just asked this question as well; the CM at WDW DINE told me 9 PM, the WDW website says 10 PM with Spectro showing at 9 & 11. So, in other words, I still don't know. I didn't get a very clear answer in my post either...
I got a phone call from the GF tonight telling me that WISHES is at 10pm on July 4th. We have the Grand One booked for that night, so they needed to know what time we'd want to leave the marina.
Do any vets know how the week after the 4th is? I had read somewhere that there is a lull after the 4th, so we're going the end of that week (thurs the 8th) thru the 16.
The disney website recently changed the time from 9 until 10. They also changed Illuminations from 10 until 9 so the changes maybe for real. I would keep checking the website.