http://dev.bukkit.org/server-mods/autoshutdown/ That plugin hasn't been updated in a while and I would really like to have it on my server. Someone posted an updated version in the comments of that plugin but it doesn't seem to work for me.
Theres a guy who made a working version This modified version work for me on 1.2.5 : http://team-frenchie.com/web/up/AutoShutdown_V_2.2.jar Rardical