I do believe the early Egyptians, being as smart as they where used a interesting method of a sundial. It caught the suns shadow and they where able to use it to tell the time.
Under Cyrus the Great, the Persians allowed the peoples they conquered to continue their lives and cultures. They could keep their customs and religion as long as they paid their taxes and obeyed the Persian rulers. This was different from how earlier conquerors such as the Assyrians had ruled.
Because they never knew when one of their family members would be sold to a separate place. They had no way to stop things from happening.