diff --git a/joint_teapot/teapot.py b/joint_teapot/teapot.py
index a017ee3..1735e24 100644
--- a/joint_teapot/teapot.py
+++ b/joint_teapot/teapot.py
@@ -319,7 +319,7 @@ class Teapot:
                     "### Submission Time Check Failed\n"
                     f"Current time {now} is not in the valid range "
                     f"[{begin_time}, {end_time}], and the penalty range "
-                    f"[{end_time}, {penalty_end_time}].\n",
+                    f"[{end_time + timedelta(seconds=1)}, {penalty_end_time}].\n",
                     True,
                 )
             else: