diff --git a/lib/ansible/plugins/filter/core.py b/lib/ansible/plugins/filter/core.py
index 573363c782..f4487f7d24 100644
--- a/lib/ansible/plugins/filter/core.py
+++ b/lib/ansible/plugins/filter/core.py
@@ -35,7 +35,7 @@ import uuid
 import yaml
 
 from collections import MutableMapping, MutableSequence
-from datetime import datetime
+import datetime
 from functools import partial
 from random import Random, SystemRandom, shuffle
 
@@ -69,6 +69,8 @@ class AnsibleJSONEncoder(json.JSONEncoder):
     def default(self, o):
         if isinstance(o, HostVars):
             return dict(o)
+        elif isinstance(o, (datetime.date, datetime.datetime)):
+            return o.isoformat()
         else:
             return super(AnsibleJSONEncoder, self).default(o)
 
@@ -126,7 +128,7 @@ def to_bool(a):
 
 
 def to_datetime(string, format="%Y-%m-%d %H:%M:%S"):
-    return datetime.strptime(string, format)
+    return datetime.datetime.strptime(string, format)
 
 
 def strftime(string_format, second=None):