Time passing when asleep.

When a player goes to bed, actual ticks pass by and if you're by a window, you can see the moon go down and the sun come up unlike the automatic time change. With that, ticks will pass by quickly making crops grow, mob spawning quickly (mob farms), etc. This will be very beneficial as one of the pains of Minecraft is going to sleep for the sole reason of getting rid of mobs, and sometimes you don't have to and don't want to. With this features, players will want to go to bed.