They don't. Availability varies, and they will obviously make fewer award seats available for dates when they think they can sell more, but there are no blackout dates whatsoever.
Cheers.
I'm trying to book an LAX-LIH one-way 331 days out right now, but there hasn't been any SAAver availability, even 10 minutes after the day opened up this morning ~ 2AM PST. I'd think that someone else got them, but I can't see anything domestic available for 12.5K, not even LAX-DFW. But search for LAX-YVR, and you can get boatloads of SAAver options that include LAX/SNA/BUR/SAN-DFW legs.
Any idea if this is a glitch, common practice, or blackout in effect? Or maybe I'm missing something....
Phone agents (2 so far) can't do anything, waiting again for one right now.