diff --git a/django/forms/extras/widgets.py b/django/forms/extras/widgets.py
index 51455780f5..4fb4869e68 100644
--- a/django/forms/extras/widgets.py
+++ b/django/forms/extras/widgets.py
@@ -134,3 +134,8 @@ class SelectDateWidget(Widget):
         s = Select(choices=choices)
         select_html = s.render(field % name, val, local_attrs)
         return select_html
+
+    def _has_changed(self, initial, data):
+        input_format = get_format('DATE_INPUT_FORMATS')[0]
+        data = datetime_safe.datetime.strptime(data, input_format).date()
+        return super(SelectDateWidget, self)._has_changed(initial, data)
\ No newline at end of file
diff --git a/tests/regressiontests/forms/tests/extra.py b/tests/regressiontests/forms/tests/extra.py
index dec97240e0..cbec105e94 100644
--- a/tests/regressiontests/forms/tests/extra.py
+++ b/tests/regressiontests/forms/tests/extra.py
@@ -17,6 +17,9 @@ from .error_messages import AssertFormErrorsMixin
 class GetDate(Form):
     mydate = DateField(widget=SelectDateWidget)
 
+class GetDateShowHiddenInitial(Form):
+    mydate = DateField(widget=SelectDateWidget, show_hidden_initial=True)
+
 class FormsExtraTestCase(unittest.TestCase, AssertFormErrorsMixin):
     ###############
     # Extra stuff #
@@ -697,6 +700,60 @@ class FormsExtraL10NTestCase(unittest.TestCase):
         w = SelectDateWidget(years=('1899',))
         self.assertEqual(w.value_from_datadict({'date_year': '1899', 'date_month': '8', 'date_day': '13'}, {}, 'date'), '13-08-1899')
 
+    def test_l10n_date_changed(self):
+        """
+        Ensure that SelectDateWidget._has_changed() works correctly with a
+        localized date format.
+        Refs #17165.
+        """
+        # With Field.show_hidden_initial=False -----------------------
+        b = GetDate({
+            'mydate_year': '2008',
+            'mydate_month': '4',
+            'mydate_day': '1',
+        }, initial={'mydate': datetime.date(2008, 4, 1)})
+        self.assertFalse(b.has_changed())
+
+        b = GetDate({
+            'mydate_year': '2008',
+            'mydate_month': '4',
+            'mydate_day': '2',
+        }, initial={'mydate': datetime.date(2008, 4, 1)})
+        self.assertTrue(b.has_changed())
+
+        # With Field.show_hidden_initial=True ------------------------
+        b = GetDateShowHiddenInitial({
+            'mydate_year': '2008',
+            'mydate_month': '4',
+            'mydate_day': '1',
+            'initial-mydate': HiddenInput()._format_value(datetime.date(2008, 4, 1))
+        }, initial={'mydate': datetime.date(2008, 4, 1)})
+        self.assertFalse(b.has_changed())
+
+        b = GetDateShowHiddenInitial({
+            'mydate_year': '2008',
+            'mydate_month': '4',
+            'mydate_day': '22',
+            'initial-mydate': HiddenInput()._format_value(datetime.date(2008, 4, 1))
+        }, initial={'mydate': datetime.date(2008, 4, 1)})
+        self.assertTrue(b.has_changed())
+
+        b = GetDateShowHiddenInitial({
+            'mydate_year': '2008',
+            'mydate_month': '4',
+            'mydate_day': '22',
+            'initial-mydate': HiddenInput()._format_value(datetime.date(2008, 4, 1))
+        }, initial={'mydate': datetime.date(2008, 4, 22)})
+        self.assertTrue(b.has_changed())
+
+        b = GetDateShowHiddenInitial({
+            'mydate_year': '2008',
+            'mydate_month': '4',
+            'mydate_day': '22',
+            'initial-mydate': HiddenInput()._format_value(datetime.date(2008, 4, 22))
+        }, initial={'mydate': datetime.date(2008, 4, 1)})
+        self.assertFalse(b.has_changed())
+
     def test_l10n_invalid_date_in(self):
         # Invalid dates shouldn't be allowed
         a = GetDate({'mydate_month':'2', 'mydate_day':'31', 'mydate_year':'2010'})