I love Joomla like I love my favorite sweater: it's old, it's ratty, but it's comfortable and does its job marvelously. Unlike the sweater, it's not easy to replace. Also unlike the sweater, I know how to teach it new things.
When publishing articles, Joomla insists on displaying the date in the format, "day Month year." Nothing wrong with that, but I'd generally want the day of the week, too. And maybe the time in certain categories, like surfing.
It turns out it's relatively easy to change the behavior, as it's something the good people of joomla.org thought about (unlike the behavior of the Prev/Next button, that is hard-coded to follow category with no option to go through all articles chronologically).
Theory: the display of the date chunk is controlled in layout files stored under layouts/joomla/content/info_block. The info block we are interested in, in this case, is created_date.php. If you look at that file (it's very short), you'll notice that the relevant line is:
<?php echo JText::sprintf('COM_CONTENT_CREATED_DATE_ON', JHtml::_('date', $displayData['item']->created, JText::_('DATE_FORMAT_LC3'))); ?>