diff --git a/hr_timesheet_time_control_begin_end/models/account_analytic_line.py b/hr_timesheet_time_control_begin_end/models/account_analytic_line.py
index fdb0a6a4e..b3d0245e8 100644
--- a/hr_timesheet_time_control_begin_end/models/account_analytic_line.py
+++ b/hr_timesheet_time_control_begin_end/models/account_analytic_line.py
@@ -109,8 +109,9 @@ def default_get(self, fields_list):
             "default_date"
         ):
             ctx = dict(self.env.context)
-            default_date_time = self.env.context.get("default_date_time")
-            if default_date_time:
+            if default_date_time := self.env.context.get("default_date_time"):
+                if isinstance(default_date_time, str):
+                    default_date_time = fields.Datetime.from_string(default_date_time)
                 ctx["default_date"] = default_date_time.date()
         vals = super(AccountAnalyticLine, self.with_context(**ctx)).default_get(
             fields_list + ["product_uom_id"]
diff --git a/hr_timesheet_time_control_begin_end/tests/test_account_analytic_line.py b/hr_timesheet_time_control_begin_end/tests/test_account_analytic_line.py
index c5b5c9d3c..68ec1377a 100644
--- a/hr_timesheet_time_control_begin_end/tests/test_account_analytic_line.py
+++ b/hr_timesheet_time_control_begin_end/tests/test_account_analytic_line.py
@@ -172,8 +172,8 @@ def test_onchange_time_end_calendar_context(self):
                 is_timesheet=1,
                 default_employee_id=self.employee.id,
                 is_my_timesheets=1,
-                default_date_time=datetime(2025, 10, 20, 3, 15, 0),
-                default_date_time_end=datetime(2025, 10, 20, 7, 0, 0),
+                default_date_time="2025-10-20 03:15:00",
+                default_date_time_end="2025-10-20 07:00:00",
                 default_time_start=5.25,  # compatibility with hr_timesheet_begin_end
                 default_time_stop=9.0,  # compatibility with hr_timesheet_begin_end
             ),