I wanted the post updated date to show instead of the published date. One can use a filter on the get_the_date and limit it to the archives and single posts etc. Not, great, tad misleading, but works for most themes (any that call get_the_date() anyway).
One can also override the theme’s function with a plugin.
Here’s the code if you just want to go the filter method:
<?php //add plugin header
function amr_use_updated_date ($the_date, $d, $post ) {
if (is_archive() or is_home() or is_front_page()
or (is_single() and $post->post_type = 'post')) {
if ( '' == $d )
$the_date = mysql2date( get_option( 'date_format' ), $post->post_modified );
else
$the_date = mysql2date( $d, $post->post_modified );
}
return $the_date;
}
add_filter ('get_the_date', 'amr_use_updated_date', 3, 99);