One aspect of time that used to be common but has mostly been lost are "Kairos" and "Chronos". Chronos time is like "A watched pot never boils" and Kairos time is like "Time flies when you are having fun". So you can cause time Dilation just by accident
http://en.wikipedia.org/wiki/Kairos
http://en.wikipedia.org/wiki/Chronos
According to Einstein, if you sit on a train and look at a clock-tower that is behind the train as it moves, you will actually not see the clock tower in your time, you are seeing it slightly in the past as you move away from it in the train. Likewise, the people that are walking around the train are supposedly moving faster than you in time, and you are aging slower than them by the very very slightest because there is a time differential.
A "Light Year" is 6,000 Miles. 6,000 Miles is called a Light year because Light takes 1 year to travel 6,000 Miles. When you look at the sky and see stars, you are actually looking at various different time periods throughout Galactic history. The Light from those stars take years and years to get to us, so you are literally looking into the past when you look at stars. A "Light Year" comes from a Gregorian year which is 365.25 days and the speed of light is 299,792,458 m/s. And one light year is 6,000 miles.
The Theory of Relativity is used to explain how 2 people or objects can be experiencing different time, while the speed of light stays constant.
http://en.wikipedia.org/wiki/Theory_of_relativity
Then Steven Hawking has proposed "Imaginary Time". I do not understand the Math behind it, but the idea is that there are multiple time lines, and we just happen to be on a certain time line. Supposedly, there are others, and there is math behind this and without it, Quantum mechanics can not be tied to statistical mechanics.
http://en.wikipedia.org/wiki/Imaginary_time