From metawiki
What is time?

A good explanation of Time is not easy to come by. Read the time wiki page and you don't really get a good idea of what it really is and where it comes from. It's the 4th dimension, but what does that even mean? And how does relativity makes it slow down when you go fast?

This author was about to make such an attempt when the lecture by Sean Carroll below was discovered and dashed any hope of providing additional insight or examples that would be more illuminating.

Neil deGrasse Tyson gives a shorter, simpler explanation. But the longer video above is well worth the watch.

Pink Floyd on the subjective experience of time.