Minus Numbers in the Timeline

Hey, so I wanted to know is there a way to make the timeline go before the number 1?
I mean can I make it go to lets say -5 ?

I want to do this because I have a Character Rig I want to setup before I start animating. And then when I start drawing in substitutions, I can just go to the untouched Rig at -1 or 0 and have the video start at 1.