Why does time seem to pass much faster for a child than for an adult? And why does it pass faster for me than for my aging parents? There might not be much valid research into why this happens, but here are some pretty educated guesses.
One is that a child must remember more events. Kids are only starting to get acquainted with their world. So their days and weeks and years are packed with way more things than an adult must remember in that same time span.
Another thought is that, when evaluating situations, we compare them to things we’ve already lived through. If this is how memory works, then consider that a week is a bigger part of a child’s life than of a grown-up’s. So a week for a child will seem like a larger span of memory-time.