diff --git a/be/app/Models/SubTask.php b/be/app/Models/SubTask.php
index 6739630..3ee4c5f 100644
--- a/be/app/Models/SubTask.php
+++ b/be/app/Models/SubTask.php
@@ -45,6 +45,7 @@ class SubTask extends Model
         $timesheets = array_map(function($item) {
             $item['user_id'] = $item['employee_id'];
             unset($item['employee_id']);
+            unset($item['timestamp']);
             $item['sub_task_id'] = $this->id;
 
             if (!$this->id) {