diff --git a/app/common/model/store/order/StoreOrderInterest.php b/app/common/model/store/order/StoreOrderInterest.php
index fd715c88..c5dc74d9 100644
--- a/app/common/model/store/order/StoreOrderInterest.php
+++ b/app/common/model/store/order/StoreOrderInterest.php
@@ -27,6 +27,9 @@ class StoreOrderInterest extends BaseModel
      */
     public function calculateInterest()
     {
+        if ($this->start_time == '0000-00-00 00:00:00') {
+            return 0;
+        }
         $days = ceil((time() - strtotime($this->start_time)) / 86400);
         $days = max($days ,0);
         $money = bcmul($this->total_price, ($this->rate / 100), 3);