Time seems to be a simple thing. And, in one sense, it is.
In many other ways, it is immensely complicated. A lot of those complications come about because of individual perceptions, which are without limit.
Have you ever had a sense that your watch seems to be running slowly while your partner says his/her watch seems to be running too fast.
Perceptions of time are indeed mysterious and very difficult to understand and explain. If you are waiting impatiently, time seems to pass very slowly? If you are distracted as time passes, time seems to fly by?
How often have you returned from a five time zone trip to discover the first afternoon back that time seems to be passing very, VERY slowly -- as you try to stay awake until bedtime? Have you ever watched a running race start, and then hear the starting gun shot moments later? Clearly the speed of sound is different from the speed of light? Why?
Some genius a long time ago -- long before telescopes, etc. -- figured out that the earth itself rotates daily and also rotates around the sun in about 52 weeks. That logically leads to 24, 60-minute hours for the daily rotation, which in turn means seven 24 hour days a week.
From there, we have today's basic time and distance system. It is not hard to see that while the physical movements remain the same, they might have been represented by comparable but different numbers.
Then Einstein figured out that the speed of light is 186,000 miles per second. (If I could explain how he reached that number, I probably would be doing something more worthwhile than simply writing this message!)
That fact by itself leads minds into a wonderland when they hear about distances like "light years," each of which translates into 5,878,499,810,000 miles -- which is a number human minds have not yet evolved fully enough to grasp.
So when one hears about stars that are 1,000,000 light years away, while it may not take your breath away, it does blur a mind into meaningless nothingness.
A question comes to mind.
Why did someone/thing create a universe so big that, using our system of time and distance that it is basically impossible for intelligent, exploring inclined beings, like humans, to even imagine ever "setting foot" on planets around a distant star?
There are a lot of possible answers.
Few serious people ever imagined that intelligent beings would be so stupid as to want to leave our comfortable Earth.
Then Jared Diamond started raising interesting and serious questions in his book, Collapse, about how societies' chose to fail or succeed, which now puts in question the inevitably of human survivability.
Perhaps someone imagined that intelligent beings would/should be satisfied with simply sending cameras out and getting pictures back?
But perhaps somewhere out there -- maybe in black holes? -- there may be other dimensions which might change our concepts of time and distance, so that "we" may be beamed out and back from a distant planet, near a very distant star, in a time measured in own 'local' time that normal humans can handle.
We need to open our minds to new possibilities about the timeless aspects of time.
If you have any interest in a great deal more authoritative information about this subject, I refer you to The Scientific American, Volume 23, No.4, Autumn 2014.