diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index 02638e3b9..496fc5b8f 100755
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -917,7 +917,7 @@ class Ami(TaggedEC2Resource):
         self.architecture = None
         self.kernel_id = None
         self.platform = None
-        self.creation_date = datetime.utcnow().isoformat()
+        self.creation_date = utc_date_and_time()
 
         if instance:
             self.instance = instance