Hi Ismh,
You need to put some of Thematic's Child Theme Overrides into you child themes functions.php Something like this might work..
function childtheme_override_postheader() {
global $post;
if ( is_404() || $post->post_type == 'page') {
$postheader = thematic_postheader_posttitle();
}
elseif (is_front_page() ){
$postheader = thematic_postheader_postmeta();
else {
$postheader = thematic_postheader_posttitle() . thematic_postheader_postmeta();
}
echo apply_filters( 'thematic_postheader', $postheader ); // Filter to override default post header
}
This would set your homepage to not show the Post title, just the PostMeta, which includes the Author, date and categories. But then to make it only show the date, you'd have to apply the Child Theme override to the thematic_postheader_postmeta function as well, this time removing the Author info and categories with an 'if is_front_page()' statement.
Hope that helps!