People have always been fascinated by the concept of altering time. Everyone has experienced the "If only I could redo that situation," "I wish I had more time to study for my test," "Can I just fast forward to Friday already?" Zack Morris was the coolest Saved by the Bell Character because he could TIME OUT!!
Something that has always bothered me about time is that people always say, if the universe ends time will still persist. I think time is similar to money in that it is a human invention. If no one is around to monitor and keep time it will not continue only the cycles of the universe. Granted, how long stars, galaxies, and the universe live will be determined by an indeterminate amount of time. But who cares "how long" it will take? People care about time, the stars, galaxies, and universe don't care about time. The objects in the universe experience cycles, but time is not a factor to them...time is only important to those who keep it, therefore, if there are no beings to track it then it ceases to exist.