Twentysixteen’s header
and functions.php
appear to support the body_class
filter.
add_filter('body_class', 'my_body_classes');
function my_body_classes($classes) {
global $wp_query;
$time = time() + ( get_option( 'gmt_offset' ) * 3600 );
$classes[] = 'w' . gmdate( 'W', $time );
if ( is_page() && $wp_query->post->post_parent ){
$classes[] = 'parent-' . $wp_query->post->post_parent;
}
return $classes;
}