We just bought a new bed, and the manufactured suggested every month, but the salesman said every two to three months was good.
How frequently should you rotate a new mattress?
Every other month seems to work for me. I think that's about the right time to keep it nice and the way you want it.
It depends on what its made of - my mattress is foam with gel, and I don't have to rotate it.
I think rotating it monthly is good idea for any type of mattress to keep it in good condition.
We rotate ours each month. Then after four rotations we switch sides for another four rotations then repeat. After a while it becomes a habit. At first I had issues not sleeping "on my side of the bed". But I realized I began to sleep better, and less back pain.