Dulles / Airport Marriott / CLOSED Weekends, New Years, Martin Luther King Jr. Day, Memorial Day, Easter, Labor Day, Thanksgiving, Christmas;lounge only serves oatmeal and coffee in the morning, elite breakfast is served from the menu in Aviate, the lobby restaurant; 06/23 update
I have an upcoming stay here and received the following in an email.
"... the lounge is open 4:30AM – 1AM the following morning seven days a week. Complimentary breakfast for our Platinum, Titanium and Ambassador guests is available in the Aviate Bar & Grille from 6AM to 11AM. If you prefer more of a grab and go breakfast option in the concierge lounge, our culinary team designs fresh parfaits and hot oatmeal .Heavy hors d’oeuvres are offered 5:30-7:30pm."