(Original post by im so academic)
Apparently you can get warned if you bump up a thread even from just 3 months ago (or around that limit).
I've seen the Coursework.info bot bump up threads from a couple of years ago.
Bumping really old threads is something that's discouraged, yes, but warnings wouldn't usually be given unless we see it being done very often. Three months is a good ballpark figure.
The bot shouldn't be bumping threads that are that old; it's set to bump threads after a day and to completely ignore threads older than seven days. If you see examples where older threads are bumped, it would be helpful if you could post links here so that this can be investigated.