Installation

Main Way

This is the basic way to do it (the other is a backup in case I am not allowed to package my plugin with joda-time):

You must have Vault plugin on your server. If not, get it here.
Download the plugin from Bukkit ONLY. This ensures that the plugin has no viruses and is safe to use since each upload is inspected by staff before being allowed to be downloadable.
Extract the zip file into your plugins folder NOTE: if a lib folder already exists then merge them together, this plugin uses joda-time which is an external library (not plugin) and needs to be contained there so it doesn't crash the server.
Start/Reload/Restart your server
Edit the config as you want it
If edited config reload or restart server again
...
Profit!

This is fairly similar to the first way but requires some extra steps, so you will see overlap in the steps here and above

You must have Vault plugin on your server. If not, get it here.
Download the plugin from Bukkit ONLY. This ensures that the plugin has no viruses and is safe to use since each upload is inspected by staff before being allowed to be downloadable.
Place the jar into your plugins folder.
Create a lib folder inside your plugins folder.
Download and place joda-time (download here). Without this the plugin will error out when prompted for age, and it is a jar dependency that is not a plugin, so if you place it into your plugins folder only (not lib) then your server will error out (just so you know: that is baaaaad!)
Start/Reload/Restart your server
Edit the config as you want it
If edited config reload or restart server again
Done!