It is expected that time travel is quite possible. Time was not created by itself, time was created by man. We have clocks, alarm, watches, etc. We have made time. If man never discovered about time, what would happen? Kids would be late for school. Parents would be late for work. Time is time. However, you can change it. You just need to exceed the speed of light. It could be from a really fast spaceship, or a vehicle. But i suppose, having super fast spaceships could be some years away from us.