Plane is sitting in PTY right now and has already been delayed leaving by 2 hours tomorrow morning after arriving 2 hours late from IAH so I'm assuming it's a crew rest thing. Plane is supposed to go to EWR and then onto DIA. My flight is still showing on time but I'm not holding my breath. Looking at a lot of other flights to AUS & IAH from DIA tomorrow and they're similar stories. Hope United figured this **** out and my flight stays on time but I'm not holding my breath.