A cron based scheduler to run any bukkit commands or plugins that extend "Runnable". This allows admins from the console or in game to create timers for various events. Also allows suspend/resume options for the timers.
Examples:
Cron is a syntax for scheduling, it is very flexible and very powerful ( though maybe a bit confusing at first ). Wikipedia has a good article on it, and there are many examples on the web. Just google "cron examples".
Brief cheat sheet from wikipedia.
* * * * * command to be executed ┬ ┬ ┬ ┬ ┬ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └─── day of week (0 - 6) (0 is Sunday, or use names) │ │ │ └──────── month (1 - 12) │ │ └───────────── day of month (1 - 31) │ └────────────────── hour (0 - 23) └─────────────────────── min (0 - 59)