diff --git a/app/code/core/Mage/CatalogRule/Model/Resource/Rule.php b/app/code/core/Mage/CatalogRule/Model/Resource/Rule.php
index 4d734d40210..712524f9e91 100644
--- a/app/code/core/Mage/CatalogRule/Model/Resource/Rule.php
+++ b/app/code/core/Mage/CatalogRule/Model/Resource/Rule.php
@@ -196,12 +196,10 @@ public function insertRuleData(Mage_CatalogRule_Model_Rule $rule, array $website
 
         $fromTime = (int) Mage::getModel('core/date')->gmtTimestamp(strtotime($rule->getFromDate()));
         $toTime = (int) Mage::getModel('core/date')->gmtTimestamp(strtotime($rule->getToDate()));
-        $toTime = $toTime ? ($toTime + self::SECONDS_IN_DAY - 1) : 0;
+        $toTime = $toTime ? strtotime('+1day - 1second', $toTime) : 0;
 
         $timestamp = time();
-        if ($fromTime > $timestamp
-            || ($toTime && $toTime < $timestamp)
-        ) {
+        if ($fromTime > strtotime('+1day', $timestamp) || ($toTime && $toTime < $timestamp)) {
             return;
         }
         $sortOrder = (int) $rule->getSortOrder();