Changing wordpress post or custom post date format is very easy. If you are using WP_Query and using while loop you can format the date with this
<?php echo date('l, F j, Y', strtotime(get_the_date())) ?>
Output will be "Friday, September 24, 2004"
If you are using get_posts() function and using foreach loop code will be like this
<?php echo date('l, F j, Y', strtotime($post->post_date)) ?>
Here are some example of formats
Format String Examples
Here are some examples of date format with the result output.
F j, Y g:i a
– November 6, 2010 12:50 amF j, Y
– November 6, 2010F, Y
– November, 2010g:i a
– 12:50 amg:i:s a
– 12:50:48 aml, F jS, Y
– Saturday, November 6th, 2010M j, Y @ G:i
– Nov 6, 2010 @ 0:50Y/m/d \a\t g:i A
– 2010/11/06 at 12:50 AMY/m/d \a\t g:ia
– 2010/11/06 at 12:50amY/m/d g:i:s A
– 2010/11/06 12:50:48 AMY/m/d
– 2010/11/06