diff --git a/Pipfile b/Pipfile
index 079e7ae..b68d0ee 100644
--- a/Pipfile
+++ b/Pipfile
@@ -9,6 +9,7 @@ psycopg2 = "*"
 pyoai = "*"
 requests = "*"
 gunicorn = "*"
+pytz = "*"
 doab-check = {editable = true, path = "."}
 
 [dev-packages]
diff --git a/Pipfile.lock b/Pipfile.lock
index c4ea5f7..bdbbccb 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,11 +1,11 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "4a11e64a7ef8724e60a36f766844c65796fce7aecee9ca371b1e6db3109afb45"
+            "sha256": "88319ac8e3e7a9d3d28deb1837d53c845d2d5f340c903f6c60de1f8b9a86f55a"
         },
         "pipfile-spec": 6,
         "requires": {
-            "python_version": "3.9"
+            "python_version": ">=3.9"
         },
         "sources": [
             {
@@ -250,6 +250,14 @@
             "index": "pypi",
             "version": "==2.5.0"
         },
+        "pytz": {
+            "hashes": [
+                "sha256:1d8ce29db189191fb55338ee6d0387d82ab59f3d00eac103412d64e0ebd0c588",
+                "sha256:a151b3abb88eda1d4e34a9814df37de2a80e301e68ba0fd856fb9b46bfbbbffb"
+            ],
+            "index": "pypi",
+            "version": "==2023.3"
+        },
         "requests": {
             "hashes": [
                 "sha256:64299f4909223da747622c030b781c0d7811e359c37124b4bd368fb8c6518baa",
@@ -260,11 +268,11 @@
         },
         "setuptools": {
             "hashes": [
-                "sha256:2ee892cd5f29f3373097f5a814697e397cf3ce313616df0af11231e2ad118077",
-                "sha256:b78aaa36f6b90a074c1fa651168723acbf45d14cb1196b6f02c0fd07f17623b2"
+                "sha256:6f0839fbdb7e3cfef1fc38d7954f5c1c26bf4eebb155a55c9bf8faf997b9fb67",
+                "sha256:bb16732e8eb928922eabaa022f881ae2b7cdcfaf9993ef1f5e841a96d32b8e0c"
             ],
             "markers": "python_full_version >= '3.7.0'",
-            "version": "==67.6.0"
+            "version": "==67.7.1"
         },
         "six": {
             "hashes": [
@@ -276,11 +284,11 @@
         },
         "sqlparse": {
             "hashes": [
-                "sha256:0323c0ec29cd52bceabc1b4d9d579e311f3e4961b98d174201d5622a23b85e34",
-                "sha256:69ca804846bb114d2ec380e4360a8a340db83f0ccf3afceeb1404df028f57268"
+                "sha256:5430a4fe2ac7d0f93e66f1efc6e1338a41884b7ddf2a350cedd20ccc4d9d28f3",
+                "sha256:d446183e84b8349fa3061f0fe7f06ca94ba65b426946ffebe6e3e8295332420c"
             ],
             "markers": "python_version >= '3.5'",
-            "version": "==0.4.3"
+            "version": "==0.4.4"
         },
         "urllib3": {
             "hashes": [
diff --git a/doab_check/doab_oai.py b/doab_check/doab_oai.py
index f1d3f89..09637b1 100644
--- a/doab_check/doab_oai.py
+++ b/doab_check/doab_oai.py
@@ -5,6 +5,10 @@ import datetime
 import logging
 import re
 
+import pytz
+from dateutil.parser import isoparse
+from dateutil.utils import default_tzinfo
+
 from oaipmh.client import Client
 from oaipmh.error import IdDoesNotExistError, NoRecordsMatchError
 from oaipmh.metadata import MetadataRegistry
@@ -84,6 +88,7 @@ def load_doab_record(doab_id, title, publisher_name, item_type, urls, timestamps
     new_item.resource_type = item_type
     new_item.save()
     for timestamp in timestamps:
+        timestamp = default_tzinfo(isoparse(timestamp), pytz.UTC)
         (new_timestamp, created) = Timestamp.objects.get_or_create(
             datetime=timestamp,
             item=new_item)
@@ -120,12 +125,12 @@ def load_doab_oai(from_date, until_date, limit=100):
     '''
     use oai feed to get oai updates
     '''
-    start = datetime.datetime.now()
+    start = datetime.datetime.now(pytz.UTC)
     if from_date:
         from_ = from_date
     else:
         # last 15 days
-        from_ = datetime.datetime.now() - datetime.timedelta(days=15)
+        from_ = datetime.datetime.now(pytz.UTC) - datetime.timedelta(days=15)
     num_doabs = 0
     new_doabs = 0
     lasttime = datetime.datetime(2000, 1, 1)
@@ -147,7 +152,7 @@ def load_doab_oai(from_date, until_date, limit=100):
                 if not item:
                     logger.error('error for doab #%s', doab)
                     continue
-                if lasttime > start:
+                if item.created > start:
                     new_doabs += 1
                 title = item.title
                 logger.info(u'updated:\t%s\t%s', doab, title)
diff --git a/doab_check/management/commands/check_items.py b/doab_check/management/commands/check_items.py
index e6ccbaf..790305f 100644
--- a/doab_check/management/commands/check_items.py
+++ b/doab_check/management/commands/check_items.py
@@ -41,7 +41,6 @@ class Command(BaseCommand):
             except Item.DoesNotExist:
                 continue
 
-        self.stdout.write(f'checked {n_checked} links')
         end_time = datetime.datetime.now()
         logger.info(f'checked {l_checked} links in {end_time - start_time}')
         self.stdout.write(f'checked {l_checked} links for {n_checked} items in {end_time - start_time}')
diff --git a/doab_check/management/commands/check_some_links.py b/doab_check/management/commands/check_some_links.py
index a9dd529..de43c68 100644
--- a/doab_check/management/commands/check_some_links.py
+++ b/doab_check/management/commands/check_some_links.py
@@ -22,7 +22,6 @@ class Command(BaseCommand):
             n_checked += 1
             if n_checked >= max:
                 break
-        self.stdout.write(f'checked {n_checked} links')
         end_time = datetime.datetime.now()
         logger.info(f'checked {n_checked} links in {end_time - start_time}')
         self.stdout.write(f'checked {n_checked} links in {end_time - start_time}')
diff --git a/setup.cfg b/setup.cfg
index d21e7a7..2585a26 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -29,4 +29,6 @@ install_requires =
     Django == 4.1.7
     psycopg2 == 2.9.5
     pyoai == 2.5.0
-    requests == 2.28.2
\ No newline at end of file
+    requests == 2.28.2
+    pytz > 2021
+    python-dateutil >= 2.8.0
\ No newline at end of file