Bukkit

A single command is used to display a custom message with the time, the date, the number of elapsed days or weeks, or many other placeholders.

/now messages support multi-language and could automatically be accorded to any player's locale available in the lang.yml file.

Using the permissions, you can permit players to choose the display and/or the world argument or neither of the two.

Display argument can be : 'msg', 'title' or 'actionbar'.

Nether and the End worlds could have a specific message.

Hexadecimal colors can be used in the YAML files.