time actually exists, it is one of the fundamental dimensions of universe together with space. And it is also true that sometimes it passes faster, it has been proved.
According to Einstein's Theory of relativity individual time goes on slowly the more you move faster in space. Example: a man is kicked in a spaceship and he is sent to Proxima Centauri at the speed of light and istantly he is sent back always at speed of light. The trip will last 9 years but the man (who has travelled at the speed of light) will sense that the trip lasted much less time, and he won't be aged like the people on earth (for whom 9 years has passed!!).
However "this time shift" is very hardly perceived at the very slow speed we're actually moving every day, but it has been showed that even in this case some kind of infinitesimal variation of time actually exists between someone who moves faster and someone who stands still or moves slowly.
Said this I have to say that your time shift/variation is actually related to the different perception of time at a psychological level and it depends from the attention we pay to present moments (when we have fun we don't pay attention to time, when we are bored we do).