Auto Publish In WordPress

Recently switched from Nucleus to WordPress and am absolutely loving this software. However, in Necleus, it was possible to write posts and have them publish automatically at a specific time. I am sure this is possible in WordPress, but I am unsure if I need a plugin or if it already included in 2.3. Maybe a newbie question, but could someone please help? I googled around for more information and/or a plugin and came up empty. What am I missing?