'date_query'            => array(
'relation'   => 'OR',
    array(
        'column'  => 'post_date',
        'after'   => '-7 days'
    ),
    array(
        'column'  => 'post_modified',
        'after'   => '-7 days'
    )
)

//order home posts by modified
function order_home_asc($query) {
  if ($query->is_home() && $query->is_main_query() && !is_admin()) {
    $query->set('orderby', 'modified');
    $query->set('order', 'DESC');
    $query->set( 'post__not_in', array( 889, 738, 1008, 808, 638) );
    $query->set('post_status', 'future,publish');
  }
}
add_action('pre_get_posts', 'order_home_asc');