[guntakeda]

Time is a man made construct. So Mins, Hours, Day, Years etc.
But the concept of time exists everywhere. No matter what part of the universe your from. However there perception of time might be different.
So what we might call a min 60 seconds - they might call it 106 (also in an alien language lol) Eg: 106 SnarfSnarf xD

Obviously it depends on how others based there calender their own time on for example. Man used the sun & the earths rotation to figure out his time. Where ever the sun is, this corrosponds to what time it is during the day.

So other beings in the universe might of based it on the same thing, But there sun(s)/moon(s) could take longer or less time to orbit.
So the answer is yes! time is real - Its just the perceptions/concepts of reading time that change.

Time travel I dont really know much about!
But it is supposed to be possible. You have to travel faster than the speed of light. Ofcourse it wont happen.
I suggest you watch Donnie Darko. It has a great plot about time travel etc & a really interesting concept of how to time travel/ what happens!