This is something you really have to watch with Air Asia. I'm largely a fan of their operation, but changing flights and then failing to notify customers is a problem that they really need to tighten up on.

I've had several experiences like this with domestic Thailand flights, and only by keeping a close eye on flights for sale have I been able to deduce that flights I had already booked had been re-timed. In one case I had an afternoon flight, on a route with only one flight per day, become an early morning flight. I purposely did not contact Air Asia to see what would happen if I didn't. Nothing happened. Had I turned up in the afternoon I would have had no option but to wait until the following day.