Rotation what? Sorry, but you need to explain better. If you used an animation preset, you need to tell us which one and to what it is applied. Otherwise, and without meaning to be rude, it seems painfully obvious that you are a newb and you may need to start at the beginning and read the help on keyframes, animation presets and all that.
So you've got two keyframes set for rotation? You adjust the timing by moving the keyframes.
As Myl says, we need more information and we'll probably ask you to review some fundamentals.