diff --git a/webapp/mt/EventRanking.php b/webapp/mt/EventRanking.php
index 20b45582..32f6125f 100644
--- a/webapp/mt/EventRanking.php
+++ b/webapp/mt/EventRanking.php
@@ -45,8 +45,8 @@ class EventRanking
             'wave' => $meta['wave'],
             'themeType' => $meta['themeType'],
             'themeName' => $meta['themeName'],
-            'startTime' => $meta['startTime'],
-            'endTime' => $meta['endTime'],
+            'startTime' => strtotime($meta['startTime']),
+            'endTime' => strtotime($meta['endTime']),
         );
         $now = myself()->_getNowTime();
         switch ($now){