diff --git a/database/migrations/2022_01_06_132023_project_tasks_update_subtask_time.php b/database/migrations/2022_01_06_132023_project_tasks_update_subtask_time.php
new file mode 100644
index 00000000..618e66f3
--- /dev/null
+++ b/database/migrations/2022_01_06_132023_project_tasks_update_subtask_time.php
@@ -0,0 +1,39 @@
+<?php
+
+use App\Models\ProjectTask;
+use Illuminate\Database\Migrations\Migration;
+
+class ProjectTasksUpdateSubtaskTime extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        ProjectTask::where('parent_id', '>', 0)
+            ->whereNull('end_at')
+            ->chunkById(100, function ($lists) {
+                /** @var ProjectTask $task */
+                foreach ($lists as $task) {
+                    $parent = ProjectTask::whereNotNull('end_at')->find($task->parent_id);
+                    if ($parent) {
+                        $task->start_at = $parent->start_at;
+                        $task->end_at = $parent->end_at;
+                        $task->save();
+                    }
+                }
+            });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        //
+    }
+}