Are you trying to do this in order to make you're dreams longer?

If so then you're wasting your time because when dreaming it's all about perception. You could live 3 years in a dream but it could be only 3 minutes in you're waking state.

Now that I've started getting back into this and actually keeping track of my dreams again, I'm planning on actually finding out a way to actually make it seem like my dreams are longer.