How frequently does the automatic transmission fluid need to be changed?

[Hamster]

Yeah, I'm sorry, I know there's five million threads on transmission fluid changes, but I can't get a straight answer on one thing: Does the automatic transmission fluid need to be changed at a fixed time, or is it based on milage alone? What I mean is, for example, when it comes to the engine oil, you change it every 5,000 or six months, whichever comes first. Are you supposed to change the transmission fluid after a certain amount of milage or time, whichever comes first (just like the engine oil), or is it just based just on milage? For the record, my car is a 2009, and has about 11,000 miles on it. I'm a low-milage driver, obviously, so I want to make sure that this is something that I won't need to worry about for a long, long time.

If it's based on milage, what is the exact interval? Different people on this forum have said different things, and the ranges people have mentioned seem to be anywhere from 30,000 to 60,000. But the general consensus seems to be that Toyota (as well as a lot of auto manufacturers) are "wrong" in saying that their automatic transmission fluids only need to be changed every 100,000 miles.

So, in summary, at what intervals does the automatic transmission fluid need to be drained and changed? And are you supposed to run away from any mechanic that wants to do a "flush"?

Sorry, I'm not a mechanic, and this is my first car. I'm just trying to make sense of all these threads about the automatic transmission fluid.