Fixed #24497 -- Added Widget.supports_microseconds attribute

django/forms/forms.py

@@ -620,7 +620,7 @@ class BoundField(object):
                     # If this is an auto-generated default date, nix the
                     # microseconds for standardized handling. See #22502.
                     if (isinstance(data, (datetime.datetime, datetime.time)) and
-                            not getattr(self.field.widget, 'supports_microseconds', True)):
+                            not self.field.widget.supports_microseconds):
                         data = data.replace(microsecond=0)
                     self._initial_value = data
         else:

django/forms/widgets.py

@@ -180,6 +180,7 @@ class Widget(six.with_metaclass(MediaDefiningClass)):
     needs_multipart_form = False  # Determines does this widget need multipart form
     is_localized = False
     is_required = False
+    supports_microseconds = True
 
     def __init__(self, attrs=None):
         if attrs is not None:

tests/forms_tests/tests/test_forms.py

@@ -1455,15 +1455,27 @@ class FormsTestCase(TestCase):
         def delayed_now_time():
             return now.time()
 
+        class HiddenInputWithoutMicrosec(HiddenInput):
+            supports_microseconds = False
+
+        class TextInputWithoutMicrosec(TextInput):
+            supports_microseconds = False
+
         class DateTimeForm(Form):
             auto_timestamp = DateTimeField(initial=delayed_now)
             auto_time_only = TimeField(initial=delayed_now_time)
             supports_microseconds = DateTimeField(initial=delayed_now, widget=TextInput)
+            hi_default_microsec = DateTimeField(initial=delayed_now, widget=HiddenInput)
+            hi_without_microsec = DateTimeField(initial=delayed_now, widget=HiddenInputWithoutMicrosec)
+            ti_without_microsec = DateTimeField(initial=delayed_now, widget=TextInputWithoutMicrosec)
 
         unbound = DateTimeForm()
         self.assertEqual(unbound['auto_timestamp'].value(), now_no_ms)
         self.assertEqual(unbound['auto_time_only'].value(), now_no_ms.time())
         self.assertEqual(unbound['supports_microseconds'].value(), now)
+        self.assertEqual(unbound['hi_default_microsec'].value(), now)
+        self.assertEqual(unbound['hi_without_microsec'].value(), now_no_ms)
+        self.assertEqual(unbound['ti_without_microsec'].value(), now_no_ms)
 
     def test_help_text(self):
         # You can specify descriptive text for a field by using the 'help_text' argument)