I'd say about 6:30pm eastern time. Just as Jerkings, Lather and Brokejaw show their smug, self important, loathesome faces to announce the days headlines would be a great time for Dubya to pop in and announce that the war had begun.
"No fair!" They would cry. "We didn't even have time to warn the Iraqis."
I think the press has already warned the Iraqis.