diff --git a/moto/kms/responses.py b/moto/kms/responses.py
index fe7d28523..831045e3c 100644
--- a/moto/kms/responses.py
+++ b/moto/kms/responses.py
@@ -269,11 +269,12 @@ class KmsResponse(BaseResponse):
 
     def schedule_key_deletion(self):
         key_id = self.parameters.get('KeyId')
+        pending_window_in_days = self.parameters.get('PendingWindowInDays')
         _assert_valid_key_id(self.kms_backend.get_key_id(key_id))
         try:
             return json.dumps({
                 'KeyId': key_id,
-                'DeletionDate': iso_8601_datetime_without_milliseconds(self.kms_backend.schedule_key_deletion(key_id))
+                'DeletionDate': iso_8601_datetime_without_milliseconds(self.kms_backend.schedule_key_deletion(key_id, pending_window_in_days))
             })
         except KeyError:
             raise JSONResponseError(404, 'Not Found', body={
diff --git a/tests/test_kms/test_kms.py b/tests/test_kms/test_kms.py
index a06a07324..218df1d8f 100644
--- a/tests/test_kms/test_kms.py
+++ b/tests/test_kms/test_kms.py
@@ -7,7 +7,6 @@ from boto.exception import JSONResponseError
 from boto.kms.exceptions import AlreadyExistsException, NotFoundException
 import sure  # noqa
 from moto import mock_kms, mock_kms_deprecated
-from moto.core.utils import iso_8601_datetime_without_milliseconds
 from nose.tools import assert_raises
 from freezegun import freeze_time
 from datetime import datetime, timedelta
@@ -660,7 +659,7 @@ def test_schedule_key_deletion():
             KeyId=key['KeyMetadata']['KeyId']
         )
         assert response['KeyId'] == key['KeyMetadata']['KeyId']
-        assert response['DeletionDate'] == iso_8601_datetime_without_milliseconds(datetime.now() + timedelta(days=30))
+        assert response['DeletionDate'] == datetime.now() + timedelta(days=30)
 
     result = client.describe_key(KeyId=key['KeyMetadata']['KeyId'])
     assert result["KeyMetadata"]["Enabled"] == False
@@ -678,7 +677,7 @@ def test_schedule_key_deletion_custom():
             PendingWindowInDays=7
         )
         assert response['KeyId'] == key['KeyMetadata']['KeyId']
-        assert response['DeletionDate'] == iso_8601_datetime_without_milliseconds(datetime.now() + timedelta(days=7))
+        assert response['DeletionDate'] == datetime.now() + timedelta(days=7)
 
     result = client.describe_key(KeyId=key['KeyMetadata']['KeyId'])
     assert result["KeyMetadata"]["Enabled"] == False