I'm working on a new extension to display the date of the articles like a calendar. The extension is based on Calendar Icon developed by Tomasz Dobrzynsk.

Check it here working on rhuk_milkyway:

Right now I made one style (classic) including 10 colors:

Features:

• CSS based - Minimal use of tables.
• W3C valid XHTML and CSS.
• Built-in nice templates.
• Restrict use on certain Sections, Categories or Articles.
• Creation or modification date.
• User may define his template.

I intend to release it after fixing a few things (the plugin doesn't work with all templates yet) and adding more templates

Hope you like it!