diff --git a/pagure/api/issue.py b/pagure/api/issue.py
index 10e2eb1..1e929c2 100644
--- a/pagure/api/issue.py
+++ b/pagure/api/issue.py
@@ -14,6 +14,7 @@ import flask
 import datetime
 import logging
 
+import arrow
 from sqlalchemy.exc import SQLAlchemyError
 
 import pagure.exceptions
@@ -518,7 +519,7 @@ def api_view_issues(repo, username=None, namespace=None):
         if since.isdigit():
             # We assume its a timestamp, so convert it to datetime
             try:
-                updated_after = datetime.datetime.fromtimestamp(int(since))
+                updated_after = arrow.get(int(since)).datetime
             except ValueError:
                 raise pagure.exceptions.APIError(
                     400, error_code=APIERROR.ETIMESTAMP)
diff --git a/pagure/lib/model.py b/pagure/lib/model.py
index f87d3dd..000dab9 100644
--- a/pagure/lib/model.py
+++ b/pagure/lib/model.py
@@ -2275,7 +2275,7 @@ class PagureGroup(BASE):
             'description': self.description,
             'group_type': self.group_type,
             'creator': self.creator.to_json(public=public),
-            'date_created': str(arrow.get(self.date_created).timestamp),
+            'date_created': str(arrow.get(self.created).timestamp),
             'members': [user.username for user in self.users]
         }
 
diff --git a/tests/test_pagure_flask_api_issue.py b/tests/test_pagure_flask_api_issue.py
index 2365a4b..b192a97 100644
--- a/tests/test_pagure_flask_api_issue.py
+++ b/tests/test_pagure_flask_api_issue.py
@@ -1647,7 +1647,7 @@ class PagureFlaskApiIssuetests(tests.SimplePagureTest):
                 'no_stones': None,
                 'order': None,
                 'priority': None,
-                "since": start,
+                "since": str(start),
                 "status": None,
                 "tags": []
               },
@@ -1673,7 +1673,7 @@ class PagureFlaskApiIssuetests(tests.SimplePagureTest):
                 'no_stones': None,
                 'order': None,
                 'priority': None,
-                "since": middle,
+                "since": str(middle),
                 "status": None,
                 "tags": []
               },
@@ -1699,7 +1699,7 @@ class PagureFlaskApiIssuetests(tests.SimplePagureTest):
                 'no_stones': None,
                 'order': None,
                 'priority': None,
-                "since": final,
+                "since": str(final),
                 "status": None,
                 "tags": []
               },
@@ -1728,7 +1728,7 @@ class PagureFlaskApiIssuetests(tests.SimplePagureTest):
                 'no_stones': None,
                 'order': None,
                 'priority': None,
-                "since": final,
+                "since": str(final),
                 "status": None,
                 "tags": []
               },