We tend to think about time only when we feel that it is passing by very slowly. And slow, under most circumstances implies unpleasantness. I remember checking my wrist watch (for the short window of time where I actually maintained a wrist watch) significantly more during the Maths period, as compared to say in Games or English. I also think my moments of extreme rage come when I, hungry as a raven, order something in a restaurant and it takes too long to be served. In travelling by bus or train, the last few stations always seem to pass by slowly.
With time and awareness, I mostly manage to offset these unpleasant events through silly stratagems- like relying on my ‘on demand day dreaming’ capacity to pass time until the last few stations, and then bringing out the weapon of music on my mobile into play. Not just for a matter of hours, but stratagems hold you good in a slow month/year too. (Which is sad, really since it suggests that life, for you is a challenge.)
All slow time experiences though are not unpleasant. For eg. when we are listening to a song that seems to describe exactly what we are going through in life at that time, the joy experienced by seeing the look on the face of people when you appear a lot more attractive than normal, the slow day which makes you tremble with pleasure because you now KNOW what you should have known all along, etc.
In Fiction- slow time refers to portions of the story where the shifting reactions of a character in a short window of time is shown. (Unpleasant awkwardness in real life makes for great reading in fiction, much like it does when we are reliving an unpleasant moment of the past.) Similarly, fast time refers to portions of the story where changes in the psyche over a period of months/years in a few sentences.