Imagine that you have a time machine. You can instantly go backwards in time but not forward. So, you can instantly go back to, say, 1985 or last night but you have to live forward to today's date in real time.
Do you ever use it? How often? How far back do you go?
I need to know because I'm working out some design issues on my prototype right now and am trying to gauge market demand. If it turns out that there is no demand, I'll just go back in time and not build the prototype.