diff --git a/cirq-google/cirq_google/engine/engine_processor_test.py b/cirq-google/cirq_google/engine/engine_processor_test.py
index 5847ffa0647..1e4c74d4886 100644
--- a/cirq-google/cirq_google/engine/engine_processor_test.py
+++ b/cirq-google/cirq_google/engine/engine_processor_test.py
@@ -808,7 +808,7 @@ def test_get_schedule_time_filter_behavior(list_time_slots):
     processor.get_schedule(from_time=datetime.timedelta(seconds=200), to_time=None)
     list_time_slots.assert_called_with('proj', 'p0', f'end_time > {now + 200}')
 
-    test_timestamp = datetime.datetime.utcfromtimestamp(52)
+    test_timestamp = datetime.datetime.fromtimestamp(52, datetime.UTC)
     utc_ts = int(test_timestamp.timestamp())
     processor.get_schedule(from_time=test_timestamp, to_time=None)
     list_time_slots.assert_called_with('proj', 'p0', f'end_time > {utc_ts}')
@@ -852,7 +852,7 @@ def test_list_reservations_time_filter_behavior(list_reservations):
     processor.list_reservations(from_time=datetime.timedelta(seconds=200), to_time=None)
     list_reservations.assert_called_with('proj', 'p0', f'end_time > {now + 200}')
 
-    test_timestamp = datetime.datetime.utcfromtimestamp(52)
+    test_timestamp = datetime.datetime.fromtimestamp(52, datetime.UTC)
     utc_ts = int(test_timestamp.timestamp())
     processor.list_reservations(from_time=test_timestamp, to_time=None)
     list_reservations.assert_called_with('proj', 'p0', f'end_time > {utc_ts}')
diff --git a/cirq-ionq/cirq_ionq/ionq_client.py b/cirq-ionq/cirq_ionq/ionq_client.py
index 5e7d9e4fce4..ccfa6f0db7d 100644
--- a/cirq-ionq/cirq_ionq/ionq_client.py
+++ b/cirq-ionq/cirq_ionq/ionq_client.py
@@ -338,7 +338,7 @@ def list_calibrations(
         """
 
         params = {}
-        epoch = datetime.datetime.utcfromtimestamp(0)
+        epoch = datetime.datetime.fromtimestamp(0, datetime.UTC)
         if start:
             params['start'] = int((start - epoch).total_seconds() * 1000)
         if end:
diff --git a/cirq-ionq/cirq_ionq/ionq_client_test.py b/cirq-ionq/cirq_ionq/ionq_client_test.py
index 50798ea037b..dad5b425e86 100644
--- a/cirq-ionq/cirq_ionq/ionq_client_test.py
+++ b/cirq-ionq/cirq_ionq/ionq_client_test.py
@@ -40,7 +40,7 @@ def test_ionq_client_invalid_remote_host():
     for invalid_url in ('', 'url', 'http://', 'ftp://', 'http://'):
         with pytest.raises(AssertionError, match='not a valid url'):
             _ = ionq.ionq_client._IonQClient(remote_host=invalid_url, api_key='a')
-        with pytest.raises(AssertionError, match=invalid_url):
+        with pytest.raises(AssertionError, match=invalid_url or None):
             _ = ionq.ionq_client._IonQClient(remote_host=invalid_url, api_key='a')
 
 
@@ -1050,8 +1050,8 @@ def test_ionq_client_list_calibrations_dates(mock_get):
     mock_get.return_value.json.return_value = {'calibrations': [{'id': '1'}, {'id': '2'}]}
     client = ionq.ionq_client._IonQClient(remote_host='http://example.com', api_key='to_my_heart')
     response = client.list_calibrations(
-        start=datetime.datetime.utcfromtimestamp(1284286794),
-        end=datetime.datetime.utcfromtimestamp(1284286795),
+        start=datetime.datetime.fromtimestamp(1284286794, datetime.UTC),
+        end=datetime.datetime.fromtimestamp(1284286795, datetime.UTC),
     )
     assert response == [{'id': '1'}, {'id': '2'}]
 
diff --git a/cirq-ionq/cirq_ionq/service_test.py b/cirq-ionq/cirq_ionq/service_test.py
index 88cc39817af..ce2957c1801 100644
--- a/cirq-ionq/cirq_ionq/service_test.py
+++ b/cirq-ionq/cirq_ionq/service_test.py
@@ -209,8 +209,8 @@ def test_service_list_calibrations():
     calibrations = [{'id': '1', 'qubits': '1'}, {'id': '2', 'qubits': 2}]
     mock_client.list_calibrations.return_value = calibrations
     service._client = mock_client
-    start = datetime.datetime.utcfromtimestamp(1284286794)
-    end = datetime.datetime.utcfromtimestamp(1284286795)
+    start = datetime.datetime.fromtimestamp(1284286794, datetime.UTC)
+    end = datetime.datetime.fromtimestamp(1284286795, datetime.UTC)
 
     listed_calibrations = service.list_calibrations(start=start, end=end, limit=10, batch_size=2)
     assert listed_calibrations[0].num_qubits() == 1