In your wordpress installation directory go to /wp-content/themes/default/single.php file and search for the_time(). You will see a line like this:
on <?php the_time(‘l, F jS, Y’) ?> <?php the_time() ?>
First instance of the_time() used parameters l, F jS, Y which represent day of the week, month, day in month and year. Second instance of the_time() returns only the time, so you’ll want to remove <?php the_time() ?> part in case you want to disable the timestamp at the end of your wordpress posts, os you may want to change parameters in first instance of the_time() to get different date format.
