The articles I created in Drupal 7 has the following at the beginning:

Submitted by xxxxxx on Sat, 12/08/2012 - 08:43

I want the date format to be: 2012-12-08 as the format above causes confusion to my readers from many countries.

I already set in Configuration -> Date and time my preferred format as below:

Long: Sunday, December 23, 2012 - 07:53
Medium: Sun, 2012-12-23 07:53
Short: 2012-12-23 07:53

But this does not seem to have any effect in article pages. Any suggestions? Thanks

Comments

Does this help:

Thanks for directing me to

Thanks for directing me to some useful discussions. I hacked the theme I am using to achieve what I want.

Basically, in the "templates/node.tpl.php" file in the theme I am using, I find the relevant bit of code:
<?php print $submitted; ?>

I replaced it with:
<?php print "Submitted by $name on ". date("Y-m-d H:i", $created); ?>