diff --git a/registry.py b/registry.py
index 8326d3c..686d83b 100755
--- a/registry.py
+++ b/registry.py
@@ -11,10 +11,11 @@ import sys
 import os
 import argparse
 import www_authenticate
-import _strptime
 from datetime import timedelta, datetime as dt
 from getpass import getpass
 from multiprocessing.pool import ThreadPool
+from dateutil.parser import parse
+from dateutil.tz import tzutc
 
 # this is a registry manipulator, can do following:
 # - list all images (including layers)
@@ -642,7 +643,7 @@ def delete_tags_by_age(registry, image_name, dry_run, hours, tags_to_keep):
             print("timestamp not found")
             continue
 
-        if dt.strptime(image_age[:-4], "%Y-%m-%dT%H:%M:%S.%f") < dt.now() - timedelta(hours=int(hours)):
+        if parse(image_age).astimezone(tzutc()) < dt.now(tzutc()) - timedelta(hours=int(hours)):
             print("will be deleted tag: {0} timestamp: {1}".format(
                 tag, image_age))
             tags_to_delete.append(tag)
@@ -661,7 +662,7 @@ def get_newer_tags(registry, image_name, hours, tags_list):
         if image_age == []:
             print("timestamp not found")
             return None
-        if dt.strptime(image_age[:-4], "%Y-%m-%dT%H:%M:%S.%f") >= dt.now() - timedelta(hours=int(hours)):
+        if parse(image_age).astimezone(tzutc()) >= dt.now(tzutc()) - timedelta(hours=int(hours)):
             print("Keeping tag: {0} timestamp: {1}".format(
                 tag, image_age))
             return tag
@@ -690,7 +691,7 @@ def get_datetime_tags(registry, image_name, tags_list):
             return None
         return {
             "tag": tag,
-            "datetime": dt.strptime(image_age[:-4], "%Y-%m-%dT%H:%M:%S.%f")
+            "datetime": parse(image_age).astimezone(tzutc())
         }
 
     print('---------------------------------')
diff --git a/requirements-build.txt b/requirements-build.txt
index 749d9d5..e3946ce 100644
--- a/requirements-build.txt
+++ b/requirements-build.txt
@@ -1,6 +1,7 @@
 certifi==2017.7.27.1
 chardet==3.0.4
 idna>=2.5
+python-dateutil==2.8.0
 requests>=2.20.0
 urllib3>=1.23
 www-authenticate==0.9.2
\ No newline at end of file
diff --git a/test.py b/test.py
index c08ffa7..ce3f757 100644
--- a/test.py
+++ b/test.py
@@ -2,6 +2,8 @@ import unittest
 
 from datetime import datetime
 
+from dateutil.tz import tzutc, tzoffset
+
 from registry import Registry, Requests, get_tags, parse_args, \
     delete_tags, delete_tags_by_age, get_error_explanation, get_newer_tags, \
     keep_images_like, main_loop, get_datetime_tags, get_ordered_tags
@@ -662,6 +664,18 @@ class TestDeleteTagsByAge(unittest.TestCase):
         delete_tags_patched.assert_called_with(
             self.registry, "imagename", False, ["image"], [])
 
+    @patch('registry.delete_tags')
+    def test_delete_tags_by_age_no_keep_with_non_utc_value(self, delete_tags_patched):
+        self.registry.get_image_age.return_value = "2017-12-27T12:47:33.511765448+02:00"
+        delete_tags_by_age(self.registry, "imagename", False, 24, [])
+        self.list_tags_mock.assert_called_with(
+            "imagename"
+        )
+        self.list_tags_mock.assert_called_with("imagename")
+        self.get_tag_config_mock.assert_called_with("imagename", "image")
+        delete_tags_patched.assert_called_with(
+            self.registry, "imagename", False, ["image"], [])
+
     @patch('registry.delete_tags')
     def test_delete_tags_by_age_keep_tags(self, delete_tags_patched):
         delete_tags_by_age(self.registry, "imagename", False, 24, ["latest"])
@@ -717,6 +731,13 @@ class TestGetNewerTags(unittest.TestCase):
                 ["latest"]
             )
 
+        def test_keep_tags_by_age_no_keep_non_utc_datetime(self):
+            self.registry.get_image_age.return_value = "2017-12-27T12:47:33.511765448+02:00"
+            self.assertEqual(
+                get_newer_tags(self.registry, "imagename", 23, ["latest"]),
+                []
+            )
+
 
 class TestGetDatetimeTags(unittest.TestCase):
 
@@ -741,7 +762,14 @@ class TestGetDatetimeTags(unittest.TestCase):
     def test_get_datetime_tags(self):
         self.assertEqual(
             get_datetime_tags(self.registry, "imagename", ["latest"]),
-            [{"tag": "latest", "datetime": datetime(2017, 12, 27, 12, 47, 33, 511765)}]
+            [{"tag": "latest", "datetime": datetime(2017, 12, 27, 12, 47, 33, 511765, tzinfo=tzutc())}]
+        )
+
+    def test_get_non_utc_datetime_tags(self):
+        self.registry.get_image_age.return_value = "2019-07-18T16:33:15.864962122+02:00"
+        self.assertEqual(
+            get_datetime_tags(self.registry, "imagename", ["latest"]),
+            [{"tag": "latest", "datetime": datetime(2019, 7, 18, 16, 33, 15, 864962, tzinfo=tzoffset(None, 7200))}]
         )
 
 
@@ -760,23 +788,23 @@ class TestGetOrderedTags(unittest.TestCase):
         get_datetime_tags_patched.return_value = [
             {
                 "tag": "e61d48b",
-                "datetime": datetime(2025, 1, 1)
+                "datetime": datetime(2025, 1, 1, tzinfo=tzutc())
             },
             {
                 "tag": "ff24a83",
-                "datetime": datetime(2024, 1, 1)
+                "datetime": datetime(2024, 1, 1, tzinfo=tzutc())
             },
             {
                 "tag": "ddd514c",
-                "datetime": datetime(2023, 1, 1)
+                "datetime": datetime(2023, 1, 1, tzinfo=tzutc())
             },
             {
                 "tag": "f4ba381",
-                "datetime": datetime(2022, 1, 1)
+                "datetime": datetime(2022, 1, 1, tzinfo=tzutc())
             },
             {
                 "tag": "9d5fab2",
-                "datetime": datetime(2021, 1, 1)
+                "datetime": datetime(2021, 1, 1, tzinfo=tzutc())
             }
         ]
         ordered_tags = get_ordered_tags(registry="registry", image_name="image", tags_list=tags, order_by_date=True)