diff --git a/lib/towerops/alerts.ex b/lib/towerops/alerts.ex
index db9343b0..e25ecf3c 100644
--- a/lib/towerops/alerts.ex
+++ b/lib/towerops/alerts.ex
@@ -80,7 +80,7 @@ defmodule Towerops.Alerts do
   def acknowledge_alert(alert, user_id) do
     alert
     |> Alert.changeset(%{
-      acknowledged_at: DateTime.utc_now(),
+      acknowledged_at: DateTime.truncate(DateTime.utc_now(), :second),
       acknowledged_by_id: user_id
     })
     |> Repo.update()
@@ -91,7 +91,7 @@ defmodule Towerops.Alerts do
   """
   def resolve_alert(alert) do
     alert
-    |> Alert.changeset(%{resolved_at: DateTime.utc_now()})
+    |> Alert.changeset(%{resolved_at: DateTime.truncate(DateTime.utc_now(), :second)})
     |> Repo.update()
   end
 
@@ -104,7 +104,7 @@ defmodule Towerops.Alerts do
     {:ok, _results} = AlertNotifier.deliver_alert_notification(alert)
 
     alert
-    |> Alert.changeset(%{email_sent_at: DateTime.utc_now()})
+    |> Alert.changeset(%{email_sent_at: DateTime.truncate(DateTime.utc_now(), :second)})
     |> Repo.update()
   end
 
diff --git a/lib/towerops/monitoring/equipment_monitor.ex b/lib/towerops/monitoring/equipment_monitor.ex
index b9c1eccb..0002fcd9 100644
--- a/lib/towerops/monitoring/equipment_monitor.ex
+++ b/lib/towerops/monitoring/equipment_monitor.ex
@@ -14,6 +14,9 @@ defmodule Towerops.Monitoring.EquipmentMonitor do
   @ping_module Application.compile_env(:towerops, :ping_module, Towerops.Monitoring.Ping)
   @poller_module Application.compile_env(:towerops, :poller_module, Towerops.Snmp.Poller)
 
+  # Suppress warnings for Mox modules that are defined at runtime during tests
+  @compile {:no_warn_undefined, [Towerops.Monitoring.PingMock, Towerops.Snmp.PollerMock]}
+
   # Client API
 
   @doc """
@@ -79,7 +82,7 @@ defmodule Towerops.Monitoring.EquipmentMonitor do
         @ping_module.ping(equipment.ip_address)
       end
 
-    now = DateTime.utc_now()
+    now = DateTime.truncate(DateTime.utc_now(), :second)
 
     {status, response_time} =
       case check_result do
@@ -122,7 +125,7 @@ defmodule Towerops.Monitoring.EquipmentMonitor do
   end
 
   defp handle_status_change(equipment, old_status, new_status) do
-    now = DateTime.utc_now()
+    now = DateTime.truncate(DateTime.utc_now(), :second)
 
     case {old_status, new_status} do
       {_, :down} ->
diff --git a/lib/towerops/snmp/discovery.ex b/lib/towerops/snmp/discovery.ex
index cc0a3d86..5a1284af 100644
--- a/lib/towerops/snmp/discovery.ex
+++ b/lib/towerops/snmp/discovery.ex
@@ -299,7 +299,7 @@ defmodule Towerops.Snmp.Discovery do
           {:ok, Equipment.t()} | {:error, Ecto.Changeset.t()}
   defp update_equipment_discovery_time(equipment) do
     equipment
-    |> Ecto.Changeset.change(last_discovery_at: DateTime.utc_now())
+    |> Ecto.Changeset.change(last_discovery_at: DateTime.truncate(DateTime.utc_now(), :second))
     |> Repo.update()
   end
 end