xdark

This simple and elegant plugin adds callendar functionality to posts. As soon as you install and activate you can find a “Event Date Select” box in post add/edit section. Choose a date for your event and it will be displayed wherever you place pugins widget. When an event is over it won’t apear anymore.
Works great with custom themes or other calendar plugins.
Features:
<ul>
<li>WordPress built in javascript date picker</li>
<li>Change thumbnail size</li>
<li>Change color, size, type of the text to displayed on the fly through the widget options</li>
<li>Layout fully customizable through a provided css stylesheet (although id’s and classes are provided, you’ll need some css skills here)</li>
</ul>

Posts To Events

This is a simple plugin for adding callendar functionality to posts.

Posts To Events vs Simple Calendar – Google Calendar Plugin