Date format customization

From the plugin FAQ:

If you wish to see more formats, please suggest one or edit the source yourself.

Why not add a filter to the plugin to allow customization of the date format?
On line 85 of wordpress-posts-timeline.php you could do something like this:

$out .= get_the_time(apply_filters( 'timeline_date_format', get_option('timeline_date_format') ), $post->ID);

I’ve not tested the above code, but from the Codex article on apply_filters, it looks like it should work.

http://wordpress.org/extend/plugins/wordpress-posts-timeline/