How to add a timestamp and author to the blog post

The WordPress Default theme has an example of the_author in the wp-content/themes/default/index.php but the code is ‘commented-out’ so it doesn’t execute. So if you wanted to display the author info with the WordPress Default theme you would changue the line in wp-content/theme/default/index.php
from:
<small><?php the_time('F jS, Y') ?> <!-- by <?php the_author() ?> --></small>
to
<small><?php the_time('F jS, Y') ?> by <?php the_author() ?> </small>

This also demonstrates the_time function. In that same template (index.php) is an example of using the template tag , the_category() , to display that post’s category/categories.

Oops, should have pointed you to http://codex.wordpress.org/Template_Tags/the_time