Gret works of literature are always developed and enriched from age to age with the growth of thought.
The poet after all belongs himself to an age and country. Shakespeare must attempt to present the universal in terms of Elizabethan England.
As the poetic vision is timeless so the poetic product tends to be so.
The dreamer, while he is dreaming certainly, does not question his dream. It is the same with the matter of time.
Our conception of time is based intirely upon our ordinary conscious thought.