title: Formatting TimeField
body: <p>I'm overriding my model admin form in order to change the format of the displayed time of a <code>TimeField</code> field:</p>
  
  <pre><code>class myTimeForm(forms.ModelForm):
      start_time = forms.TimeField(widget=forms.TimeInput(format='%H:%M'))
      class Meta:
          model = MyModel
  
  class MyModelAdmin(admin.ModelAdmin):
      form = myTimeForm
  </code></pre>
  
  <p>Now, the <code>now</code> and the clock button I had with the default form have disappeared (in the screenshot below <code>Start time</code> is with the overridden widget, <code>End time</code> with the default one. </p>
  
  <p><img src="https://i.stack.imgur.com/F5C7t.png" alt="enter image description here"></p>
  
  <p>What did I miss?</p>