diff --git a/changelog.txt b/changelog.txt
index f7474b88..2511de98 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -33,6 +33,7 @@ Planned for 1.9
 - Feature:  (Tomino2112)      Work Item GH-808  - MemoryDrawing not working in HTML writer
 - General:  (rentalhost)      Work Item GH-575  - Excel 2007 Reader freezes because of conditional formatting
 - Bugfix:   (vitalyrepin)     Pull Request 869  - c:max and c:min elements shall NOT be inside c:orientation elements
+- General:  (sim642)          Pull Request 489  - Implement actual timezone adjustment into PHPExcel_Shared_Date::PHPToExcel
 
 
 2015-04-30 (v1.8.1):
diff --git a/src/PhpSpreadsheet/Shared/Date.php b/src/PhpSpreadsheet/Shared/Date.php
index d1ea52d1..0cf94b89 100644
--- a/src/PhpSpreadsheet/Shared/Date.php
+++ b/src/PhpSpreadsheet/Shared/Date.php
@@ -184,10 +184,17 @@ class Date
     {
         $saveTimeZone = date_default_timezone_get();
         date_default_timezone_set('UTC');
+
+        $timezoneAdjustment = ($adjustToTimezone) ?
+            PHPExcel_Shared_TimeZone::getTimezoneAdjustment($timezone ? $timezone : $saveTimeZone, $dateValue) :
+            0;
+
         $retValue = false;
         if ((is_object($dateValue)) && ($dateValue instanceof \DateTime)) {
+            $dateValue->add(new DateInterval('PT' . $timezoneAdjustment . 'S'));
             $retValue = self::formattedPHPToExcel($dateValue->format('Y'), $dateValue->format('m'), $dateValue->format('d'), $dateValue->format('H'), $dateValue->format('i'), $dateValue->format('s'));
         } elseif (is_numeric($dateValue)) {
+            $dateValue += $timezoneAdjustment;
             $retValue = self::formattedPHPToExcel(date('Y', $dateValue), date('m', $dateValue), date('d', $dateValue), date('H', $dateValue), date('i', $dateValue), date('s', $dateValue));
         } elseif (is_string($dateValue)) {
             $retValue = self::stringToExcel($dateValue);