I think time is merely a component of one's reality. That's why our perceptions of certain times are different. The old saying "Time flies when your having fun" is merely proof that time is something that you percieve and understand depending on your conscience. Thus, I think that time itself is self controlled based on perception. Like when your adrenline increases, time slows down. You may think time is constant, but in reality, it's not. It's our pure perception. It's hard to break away from this because we've made a way of "measuring" time, but before humans made clocks and ways to schedule "time", what was there? We base time off the sun, but that's not true. In other galaxies, time exists. What time is it there? It all depends upon perception.
So, back to time travel. I think that it truely depends upon your perception. I don't believe in the ability to make a machine and throw you in a certain time period, but I do believe that if one were to change their perception, they would be able to, in a sense, recreate their own reality in any time period they wish. Is that real time travel? I believe so, but that's just personal opinion. I mean, what is reality? When you dream, you think that's reality. So is this reality that we're in now? I don't know, that's a different topic.