title: Django Admin: Using a custom widget for only one model field
body: <p>I have a <a href="https://docs.djangoproject.com/en/dev/ref/models/fields/#django.db.models.DateTimeField" rel="noreferrer">DateTimeField</a> field in my model. I wanted to display it as a checkbox widget in the Django admin site. To do this, I created a custom form widget. However, I do not know how to use my custom widget for <strong>only</strong> this one field.</p>
  
  <p>The <a href="https://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.formfield_overrides" rel="noreferrer">Django documentation</a> explains how to use a custom widget for <strong>all</strong> fields of a certain type:</p>
  
  <pre><code>class StopAdmin(admin.ModelAdmin):
      formfield_overrides = {
          models.DateTimeField: {'widget': ApproveStopWidget }
      }
  </code></pre>
  
  <p>This is not granular enough though. I want to change it for only <strong>one</strong> field.</p>