diff --git a/graphene_django/tests/models.py b/graphene_django/tests/models.py
index 7ca76cf..9e7be29 100644
--- a/graphene_django/tests/models.py
+++ b/graphene_django/tests/models.py
@@ -91,8 +91,8 @@ class CNNReporter(Reporter):
 
 class Article(models.Model):
     headline = models.CharField(max_length=100)
-    pub_date = models.DateField()
-    pub_date_time = models.DateTimeField()
+    pub_date = models.DateField(auto_now_add=True)
+    pub_date_time = models.DateTimeField(auto_now_add=True)
     reporter = models.ForeignKey(
         Reporter, on_delete=models.CASCADE, related_name="articles"
     )