Possible Duplicate:
Does time pass on a Minecraft SMP server if nobody is logged on?
What happens in the minecraft server when there are no players? Will my wheat still grow? Will animals continues to spawn?
Possible Duplicate:
Does time pass on a Minecraft SMP server if nobody is logged on?
What happens in the minecraft server when there are no players? Will my wheat still grow? Will animals continues to spawn?
In general, chunks only 'update' when they are loaded, and they are only loaded when a player is in that chunk.
However, there is a bukkit plugin called 'Forever A-load' you can get for a bukkit enabled server that can enable certain chunks to always be active so things like wheat will grow, redstone will always be active and the like.