diff --git a/evergreen.py b/evergreen.py
index 51513ac..6719c59 100644
--- a/evergreen.py
+++ b/evergreen.py
@@ -80,9 +80,7 @@ def main():  # pragma: no cover
         except github3.exceptions.NotFoundError:
             pass
 
-        if created_after_date and repo.created_at.replace(
-            tzinfo=None
-        ) < datetime.strptime(created_after_date, "%Y-%m-%d"):
+        if is_repo_created_date_before(repo.created_at, created_after_date):
             continue
 
         print("Checking " + repo.full_name)
@@ -161,8 +159,18 @@ def main():  # pragma: no cover
     print("Done. " + str(count_eligible) + " repositories were eligible.")
 
 
+def is_repo_created_date_before(repo_created_at: str, created_after_date: str):
+    """Check if the repository was created before the created_after_date"""
+    repo_created_at_date = datetime.fromisoformat(repo_created_at).replace(tzinfo=None)
+    return created_after_date and repo_created_at_date < datetime.strptime(
+        created_after_date, "%Y-%m-%d"
+    )
+
+
 def is_dependabot_security_updates_enabled(owner, repo, access_token):
-    """Check if Dependabot security updates are enabled at the /repos/:owner/:repo/automated-security-fixes endpoint using the requests library"""
+    """Check if Dependabot security updates are enabled at the
+    /repos/:owner/:repo/automated-security-fixes endpoint using the requests library
+    """
     url = f"https://api.github.com/repos/{owner}/{repo}/automated-security-fixes"
     headers = {
         "Authorization": f"Bearer {access_token}",
diff --git a/test_evergreen.py b/test_evergreen.py
index 189375c..15aafcf 100644
--- a/test_evergreen.py
+++ b/test_evergreen.py
@@ -15,6 +15,7 @@
     get_global_project_id,
     get_repos_iterator,
     is_dependabot_security_updates_enabled,
+    is_repo_created_date_before,
     link_item_to_project,
 )
 
@@ -579,5 +580,45 @@ def test_link_item_to_project_request_exception(self, mock_post):
             self.assertIsNone(result)
 
 
+class TestIsRepoCreateDateBeforeCreatedAfterDate(unittest.TestCase):
+    """Test the is_repo_create_date_before_created_after_date function in evergreen.py"""
+
+    def test_is_repo_create_date_before_created_after_date(self):
+        """Test the repo.created_at date is before created_after_date."""
+        repo_created_at = "2020-01-01T05:00:00Z"
+        created_after_date = "2021-01-01"
+
+        result = is_repo_created_date_before(repo_created_at, created_after_date)
+
+        self.assertTrue(result)
+
+    def test_is_repo_create_date_is_after_created_after_date(self):
+        """Test the repo.created_at date is after created_after_date."""
+        repo_created_at = "2022-01-01T05:00:00Z"
+        created_after_date = "2021-01-01"
+
+        result = is_repo_created_date_before(repo_created_at, created_after_date)
+
+        self.assertFalse(result)
+
+    def test_is_repo_created_date_has_no_time_zone(self):
+        """Test the repo.created_at date is after created_after_date."""
+        repo_created_at = "2020-01-01"
+        created_after_date = "2021-01-01"
+
+        result = is_repo_created_date_before(repo_created_at, created_after_date)
+
+        self.assertTrue(result)
+
+    def test_is_created_after_date_is_empty_string(self):
+        """Test the repo.created_at date is after created_after_date."""
+        repo_created_at = "2020-01-01"
+        created_after_date = ""
+
+        result = is_repo_created_date_before(repo_created_at, created_after_date)
+
+        self.assertFalse(result)
+
+
 if __name__ == "__main__":
     unittest.main()