One of the factors that must be considered when attempting to date the earth and universe is time. Whether the universe is young or old, it has changed to some degree with time. Scientist Donald Chittick writes.

A veil to our understanding of what the original earth was like, and therefore how changes which have occurred since have affected it is the factor of time. By ordinary human standards, creation took place a long time ago. Even if we take the position that creation took place a few thousand years ago, this is still a long time by human standards. A lot of changes can take place even in a thousand years. Time itself has erased many of the details and much of the evidence. Some of the human artifacts may have rotted completely while others have deteriorated; geological features, erosion, and other physical changes have destroyed some of the original evidence. Time is one of the major veils to our understanding of the original earth and to our attempts to reconstruct its condition (Donald Chittick, The Controversy, Portland, Oregon, Multnomah, 1984, p. 186).

Therefore whenever we approach the question of the age of the earth and universe, we must consider the factor of time.