Adding a post calendar icon to the Twenty Ten WordPress theme to display the publish-date is a simple task, that only requires adding a little code to the loop.php and style.css files. We are going to style the Calendar with pure CSS, instead of using a background image.

The Code for Loop.php

So first we are going to open up the editor under the Appearance tab and click on the loop.php template, then we are going to scroll about half way down the page till we see the Aside format and we are going to paste the code above right after the “entry-content” div.

Then we are going to scroll down the page a little bit more until you see “How to display all other posts.” and we are going to paste the code right above the “entry-title”. So the that title will display in-line with our calendar icon.

Now we can update the file and open up the stylesheet (style.css).

The Code for style.css

Now we can copy and Paste the CSS above into our stylesheet ( style.css ) somewhere in the middle, I put mine down toward the bottom right before   /*=Print Style*/.  And thats it we are all done, you can now style it how you like changing the colors and removing the radius and shadows if you like, you can also style it with a background-image.