Hmm VS Completely Booked to NY 29th Jan

Am trying to book UC to NY, out 29th, back Feb 4th. The Web sites says there are no flights available, +/- 3 days too!
Can they be completely booked, Web site glitch, or are they prepping for a UC sale and the system is temporarily saying 'computer says no'!
Can they be completely booked, Web site glitch, or are they prepping for a UC sale and the system is temporarily saying 'computer says no'!