From bf7b6d643108df5cafc21af910c4199949a21d60 Mon Sep 17 00:00:00 2001
From: susuper <githubcom.kwun@emailserviceforpro.com>
Date: Thu, 3 Mar 2016 14:12:39 +0700
Subject: [PATCH] Changed Last-Modified HTTP header format

---
 flight/Engine.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flight/Engine.php b/flight/Engine.php
index 0ac148a..f364e21 100644
--- a/flight/Engine.php
+++ b/flight/Engine.php
@@ -507,7 +507,7 @@ class Engine {
      * @param int $time Unix timestamp
      */
     public function _lastModified($time) {
-        $this->response()->header('Last-Modified', date(DATE_RFC1123, $time));
+        $this->response()->header('Last-Modified', gmdate('D, d M Y H:i:s \G\M\T', $time));
 
         if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) &&
             strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) === $time) {