"24 hours before all flights provided by Delta Air Lines and Air France flights departing from Atlanta, Detroit and Minneapols"
"* 24 hours before flights departing to the following cities in the United States: Atlanta, Cincinnati, Detroit, Minneapolis, New York-Newark, Pittsburgh and Philadelphia."
They fly to more cities than these. My assumption is that for their own flights it is 30 hour and for delta's, 24. But I can't find a confirmation of this anywhere.