diff --git a/lib/custom_logger.js b/lib/custom_logger.js
index 6ba0514bf0d4d63b9d6944dcfd1c32cc8fda9dc9..218c803aa3ef5875eeb26015d52ac5536704ef89 100644
--- a/lib/custom_logger.js
+++ b/lib/custom_logger.js
@@ -10,12 +10,10 @@
 var logger = require('express').logger;
 
 logger.format('default_bid',
-    ':remote-addr - - :date-millis ":method :url HTTP/:http-version" :status :res[content-length] ":referrer" ":user-agent"');
+    ':remote-addr - - :date-millis ":method :url HTTP/:http-version" :status :response-time :res[content-length] ":referrer" ":user-agent"');
 
-logger.format('dev_bid', ':date-millis :method :url :status :response-time ms');
+logger.format('dev_bid', ':date-millis :method :url :status :response-time');
 
 logger.token('date-millis', function (req) {
-  var d = req._startTime,
-      t = '' + d.getTime();
-  return '[' + d.toUTCString() + ']@' + t.slice(-4);
+  return '[' + req._startTime.toISOString() + ']';
 });
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