It's also a 6/4/2 window, and it runs in the evenings (around 6pm - 10PM PST, give or take). CO is a bit better at the holdback than NW is. You'll often see seats metered out over days instead of in a lump sum like NW.
Originally Posted by mnredfox
I'm on a NWA itin with a NW leg and CO leg for Friday, and have already been EUA'd for the NW portion yesterday (which is after the CO segment)
The time of the flight doesn't have any relevance to EUA. It's done by days before not hours before.