From 532a010e0eac8df5519ab4f717ec663ff64445da Mon Sep 17 00:00:00 2001
From: Steve Clay <steve@mrclay.org>
Date: Mon, 3 Apr 2017 16:01:21 -0400
Subject: [PATCH] Parse LastModified date without requiring global timezone

---
 lib/HTTP/ConditionalGet.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/HTTP/ConditionalGet.php b/lib/HTTP/ConditionalGet.php
index 0f251ee..bbfe089 100644
--- a/lib/HTTP/ConditionalGet.php
+++ b/lib/HTTP/ConditionalGet.php
@@ -360,7 +360,10 @@ class HTTP_ConditionalGet
         }
         // strip off IE's extra data (semicolon)
         list($ifModifiedSince) = explode(';', $_SERVER['HTTP_IF_MODIFIED_SINCE'], 2);
-        if (strtotime($ifModifiedSince) >= $this->_lmTime) {
+
+        $date = new DateTime($ifModifiedSince, new DateTimeZone('UTC'));
+
+        if ($date->getTimestamp() >= $this->_lmTime) {
             // Apache 2.2's behavior. If there was no ETag match, send the
             // non-encoded version of the ETag value.
             $this->_headers['ETag'] = $this->normalizeEtag($this->_etag);