BTW, I checked sunrise/sunset times on my PDA planetarium program.
For the Phoenix area, middle of NARAM week, twilight is at 5:14am, sunrise at 5:42, sunset at 19:27, and dusk at 19:54.
So it looks like the most we could move the start time up would be to 6am.
It WILL be HOT once the sun gets up. Ad I'll kill the first person who says ...