IMO, thus page are for describing format that are understood by PHP's date parser, 
like strtotime().

for formatting date, you should consult to:
http://www.php.net/manual/en/function.date.php

This bug has been fixed in the documentation's XML sources. Since the
online and downloadable versions of the documentation need some time
to get updated, we would like to ask you to be a bit patient.

Thank you for the report, and for helping us make our documentation better.

I think there's confusion about what these pages actually document: these are the 
date formats that PHP's date parser accepts, rather than formatting codes for 
things like date(). I've added a paragraph to each page briefly explaining what 
it is.