mahodder

add_action( 'pre_get_posts', 'custom_reverse_post_order' );
function custom_reverse_post_order( $query ) {
	if ( is_admin() )
		return;
	if ( $query->is_main_query() && is_archive() && ! is_post_type_archive() && ($query->query_vars['category_name'] == 'category-name' || $query->query_vars['category_name'] == 'category-name')  ) {
		$query->set( 'orderby', 'date' );
		$query->set( 'order', 'ASC' );
	}
}