--- a/jaxp/src/com/sun/org/apache/xalan/internal/lib/ExsltDatetime.java	Thu Apr 12 08:38:26 2012 -0700
+++ b/jaxp/src/com/sun/org/apache/xalan/internal/lib/ExsltDatetime.java	Tue Apr 17 11:17:59 2012 -0700
@@ -97,7 +97,7 @@
         // In a few cases, the time zone may be +/-hh:30.
         int min = offset%(60*60*1000);
         char posneg = hrs < 0? '-': '+';
-        buff.append(posneg + formatDigits(hrs) + ':' + formatDigits(min));
+        buff.append(posneg).append(formatDigits(hrs)).append(':').append(formatDigits(min));
       }
       return buff.toString();
     }