PROFITS:
-You will know when you're going to be able to do another daily quest.
-More organization, clan banks can open at a specific time, or you can meet with a friend at a certain time to go level

-If a world wants to do a party at tavern, or try to kill Aggragoth, they can set a time to meet and do it.
Maybe you can investigate about the celtic calendary and they way to take the time, and use it in the game.
Or you can make an actual time system, and at 8 PM the sky turns dark
