Not a mod, but usually I would stream it and save the stream on a computer in which you can overlay a timer and send it off to youtube, or if you're lazy like me then I would use a real life timer in which you time yourself, making sure that you're time is right based by looking back at yourself on the stream, adjust the time if it seems off.

I understand this isn't my job as I'm not a mod but just wanted to help :]