July 4th, 2007 is a Wednesday. So, which weekend is the "holiday weekend", 6/29 - 7/1 or 7/6 - 7/8?? Online and real-world opinion that I've surveyed is right about 50-50. Kinda makes it hard to plan something when you don't know when exactly the traffic will be bad.
I kind of old and such. I remember when a "holiday" fell on the day it fell on and three day weekends were unheard of. For me July 4th is a celebration of the founding of my country. I also do crazy stuff like attend the Memorial Day service at the cemetary to honor our military. I sympathize with needing time off but does it matter which weekend it is. But to answer your question, the previous Saturday is June 30 so I vote for the wekend after.
Read the recaps the cast members posted on their personal sites (I believe they were all mentioned here earlier, so I'll recap at the end of the post) and you'll get some insight on how truly clueless the people were behind the show.