I'm not sure what the sept. photo contest is going to be yet.

As far as the rules here's a link to the rules of the photo contest:
http://ball-pythons.net/forums/showthread.php?t=25833

The rule you're specifically looking for is this:

7. The cutoff for submissions is midnight (EST) the last day of the month. No entries will be accepted after that time.

Hope this helps!