Early afternoon, like 2 or 3pm central is good for me. Anywhere around there.
EDIT: Hmm. Looks like you're British, so I suppose saying 'central time' isn't going to do it. According to the happy little clock on the main competition page I am 5 hours behind UTC. So I am proposing 1900 or 2000 UTC. If that's too late for you I can do a bit earlier. Pesky time zones.