How do I find out how many hours I have been in create mode?

I was lucky enough to get into the Beta before Christmas and was wondering where I would check to see how many hours I have put into the create mode so far?
I have just been building characters and buildings so far but it is taking me ages to put in the little details that I like. I am getting better but I seem to be constantly fighting to get the imp to stay in the right place even now after all these weeks.