Solution to order posts by two different meta values (the same way ORDER val1, val2 would with SQL) http://wordpress.stackexchange.com/a/67391/5045

order_by_multiple_meta_values.php

<?php 
/*
 * Solution to order first by date, then by start time (both are meta values)
 * http://wordpress.stackexchange.com/a/67391/5045
 * */
add_action( 'pre_get_posts', 'pre_get_posts_programpunkter' );

function pre_get_posts_programpunkter( $query ) {
	
	if( !is_admin()  && is_post_type_archive( 'programpunkt' ) && $query->is_main_query() ) {
		
		$query->set( 'orderby', 'meta_value' );
		$query->set( 'meta_key', 'event-date' );
			
		$query->set( 'meta_query', array(
			'relation' => 'AND', 
				array( 'key' => 'event-date', 'compare' => 'EXISTS' ), 
				array( 'key' => 'event-start', 'compare' => 'EXISTS' ) 
			) 
		);
			
		$query->set( 'order', 'ASC' );
				
	}
}

add_filter('posts_orderby', 'programpunkter_orderby');

function programpunkter_orderby( $orderby ) {
	
	if( get_queried_object()->query_var === 'programpunkt' )  {
		
		global $wpdb;		
		$orderby = str_replace( $wpdb->prefix.'postmeta.meta_value', 'mt1.meta_value, mt2.meta_value', $orderby );	
		
	}	
	return $orderby;
}