Index: src/main/php/helpers/LoggerDatePatternConverter.php
===================================================================
--- src/main/php/helpers/LoggerDatePatternConverter.php	(revision 931486)
+++ src/main/php/helpers/LoggerDatePatternConverter.php	(working copy)
@@ -47,7 +47,7 @@
 	public function convert($event) {
 		$timeStamp = $event->getTimeStamp();
 		$usecs = round(($timeStamp - (int)$timeStamp) * 1000);
-		$this->df = preg_replace('/((?<!\\\\)(?:\\\\{2})*)u/', '${1}' . sprintf('%03d', $usecs), $this->df);
-		return date($this->df, $event->getTimeStamp());
+		$df = preg_replace('/((?<!\\\\)(?:\\\\{2})*)u/', '${1}' . sprintf('%03d', $usecs), $this->df);
+		return date($df, $timeStamp);
 	}
 }