Billing / generation of Invoices finished

lib/mvcfronk/mfLayout/mfLayout.php

@@ -198,6 +198,10 @@ class mfLayout {
         return $url;
     }
 
+    public static function getHumanReadableInterval($seconds) {
+        return sprintf("%02d:%02d:%02d", floor($seconds / 3600), ($seconds / 60) % 60, $seconds % 60);
+    }
+
     public static function getResourcePath() {
         if (MFUSEFANCYURLS) {
             $path = MFFANCYBASEURL;