diff --git a/homeassistant/components/nest/__init__.py b/homeassistant/components/nest/__init__.py
index e4be96cbf14..1240d30f027 100644
--- a/homeassistant/components/nest/__init__.py
+++ b/homeassistant/components/nest/__init__.py
@@ -138,6 +138,7 @@ class SignalUpdateCallback:
             message = {
                 "device_id": device_entry.id,
                 "type": event_type,
+                "timestamp": event_message.timestamp,
             }
             self._hass.bus.async_fire(NEST_EVENT, message)
 
diff --git a/tests/components/nest/test_device_trigger.py b/tests/components/nest/test_device_trigger.py
index 29091f32f51..b7c75862153 100644
--- a/tests/components/nest/test_device_trigger.py
+++ b/tests/components/nest/test_device_trigger.py
@@ -10,6 +10,7 @@ from homeassistant.components.device_automation.exceptions import (
 from homeassistant.components.nest import DOMAIN
 from homeassistant.components.nest.events import NEST_EVENT
 from homeassistant.setup import async_setup_component
+from homeassistant.util.dt import utcnow
 
 from .common import async_setup_sdm_platform
 
@@ -213,7 +214,7 @@ async def test_fires_on_camera_motion(hass, calls):
     """Test camera_motion triggers firing."""
     assert await setup_automation(hass, DEVICE_ID, "camera_motion")
 
-    message = {"device_id": DEVICE_ID, "type": "camera_motion"}
+    message = {"device_id": DEVICE_ID, "type": "camera_motion", "timestamp": utcnow()}
     hass.bus.async_fire(NEST_EVENT, message)
     await hass.async_block_till_done()
     assert len(calls) == 1
@@ -224,7 +225,7 @@ async def test_fires_on_camera_person(hass, calls):
     """Test camera_person triggers firing."""
     assert await setup_automation(hass, DEVICE_ID, "camera_person")
 
-    message = {"device_id": DEVICE_ID, "type": "camera_person"}
+    message = {"device_id": DEVICE_ID, "type": "camera_person", "timestamp": utcnow()}
     hass.bus.async_fire(NEST_EVENT, message)
     await hass.async_block_till_done()
     assert len(calls) == 1
@@ -235,7 +236,7 @@ async def test_fires_on_camera_sound(hass, calls):
     """Test camera_person triggers firing."""
     assert await setup_automation(hass, DEVICE_ID, "camera_sound")
 
-    message = {"device_id": DEVICE_ID, "type": "camera_sound"}
+    message = {"device_id": DEVICE_ID, "type": "camera_sound", "timestamp": utcnow()}
     hass.bus.async_fire(NEST_EVENT, message)
     await hass.async_block_till_done()
     assert len(calls) == 1
@@ -246,7 +247,7 @@ async def test_fires_on_doorbell_chime(hass, calls):
     """Test doorbell_chime triggers firing."""
     assert await setup_automation(hass, DEVICE_ID, "doorbell_chime")
 
-    message = {"device_id": DEVICE_ID, "type": "doorbell_chime"}
+    message = {"device_id": DEVICE_ID, "type": "doorbell_chime", "timestamp": utcnow()}
     hass.bus.async_fire(NEST_EVENT, message)
     await hass.async_block_till_done()
     assert len(calls) == 1
@@ -257,7 +258,11 @@ async def test_trigger_for_wrong_device_id(hass, calls):
     """Test for turn_on and turn_off triggers firing."""
     assert await setup_automation(hass, DEVICE_ID, "camera_motion")
 
-    message = {"device_id": "wrong-device-id", "type": "camera_motion"}
+    message = {
+        "device_id": "wrong-device-id",
+        "type": "camera_motion",
+        "timestamp": utcnow(),
+    }
     hass.bus.async_fire(NEST_EVENT, message)
     await hass.async_block_till_done()
     assert len(calls) == 0
@@ -267,7 +272,11 @@ async def test_trigger_for_wrong_event_type(hass, calls):
     """Test for turn_on and turn_off triggers firing."""
     assert await setup_automation(hass, DEVICE_ID, "camera_motion")
 
-    message = {"device_id": DEVICE_ID, "type": "wrong-event-type"}
+    message = {
+        "device_id": DEVICE_ID,
+        "type": "wrong-event-type",
+        "timestamp": utcnow(),
+    }
     hass.bus.async_fire(NEST_EVENT, message)
     await hass.async_block_till_done()
     assert len(calls) == 0
diff --git a/tests/components/nest/test_events.py b/tests/components/nest/test_events.py
index 12314f60561..7295d134087 100644
--- a/tests/components/nest/test_events.py
+++ b/tests/components/nest/test_events.py
@@ -54,7 +54,7 @@ def create_device_traits(event_trait):
     }
 
 
-def create_event(event_type, device_id=DEVICE_ID):
+def create_event(event_type, device_id=DEVICE_ID, timestamp=None):
     """Create an EventMessage for a single event type."""
     events = {
         event_type: {
@@ -65,12 +65,14 @@ def create_event(event_type, device_id=DEVICE_ID):
     return create_events(events=events, device_id=device_id)
 
 
-def create_events(events, device_id=DEVICE_ID):
+def create_events(events, device_id=DEVICE_ID, timestamp=None):
     """Create an EventMessage for events."""
+    if not timestamp:
+        timestamp = utcnow()
     return EventMessage(
         {
             "eventId": "some-event-id",
-            "timestamp": utcnow().isoformat(timespec="seconds"),
+            "timestamp": timestamp.isoformat(timespec="seconds"),
             "resourceUpdate": {
                 "name": device_id,
                 "events": events,
@@ -102,15 +104,18 @@ async def test_doorbell_chime_event(hass):
     assert device.model == "Doorbell"
     assert device.identifiers == {("nest", DEVICE_ID)}
 
+    timestamp = utcnow()
     await subscriber.async_receive_event(
-        create_event("sdm.devices.events.DoorbellChime.Chime")
+        create_event("sdm.devices.events.DoorbellChime.Chime", timestamp=timestamp)
     )
     await hass.async_block_till_done()
 
+    event_time = timestamp.replace(microsecond=0)
     assert len(events) == 1
     assert events[0].data == {
         "device_id": entry.device_id,
         "type": "doorbell_chime",
+        "timestamp": event_time,
     }
 
 
@@ -126,15 +131,18 @@ async def test_camera_motion_event(hass):
     entry = registry.async_get("camera.front")
     assert entry is not None
 
+    timestamp = utcnow()
     await subscriber.async_receive_event(
-        create_event("sdm.devices.events.CameraMotion.Motion")
+        create_event("sdm.devices.events.CameraMotion.Motion", timestamp=timestamp)
     )
     await hass.async_block_till_done()
 
+    event_time = timestamp.replace(microsecond=0)
     assert len(events) == 1
     assert events[0].data == {
         "device_id": entry.device_id,
         "type": "camera_motion",
+        "timestamp": event_time,
     }
 
 
@@ -150,15 +158,18 @@ async def test_camera_sound_event(hass):
     entry = registry.async_get("camera.front")
     assert entry is not None
 
+    timestamp = utcnow()
     await subscriber.async_receive_event(
-        create_event("sdm.devices.events.CameraSound.Sound")
+        create_event("sdm.devices.events.CameraSound.Sound", timestamp=timestamp)
     )
     await hass.async_block_till_done()
 
+    event_time = timestamp.replace(microsecond=0)
     assert len(events) == 1
     assert events[0].data == {
         "device_id": entry.device_id,
         "type": "camera_sound",
+        "timestamp": event_time,
     }
 
 
@@ -174,15 +185,18 @@ async def test_camera_person_event(hass):
     entry = registry.async_get("camera.front")
     assert entry is not None
 
+    timestamp = utcnow()
     await subscriber.async_receive_event(
-        create_event("sdm.devices.events.CameraPerson.Person")
+        create_event("sdm.devices.events.CameraPerson.Person", timestamp=timestamp)
     )
     await hass.async_block_till_done()
 
+    event_time = timestamp.replace(microsecond=0)
     assert len(events) == 1
     assert events[0].data == {
         "device_id": entry.device_id,
         "type": "camera_person",
+        "timestamp": event_time,
     }
 
 
@@ -209,17 +223,21 @@ async def test_camera_multiple_event(hass):
         },
     }
 
-    await subscriber.async_receive_event(create_events(event_map))
+    timestamp = utcnow()
+    await subscriber.async_receive_event(create_events(event_map, timestamp=timestamp))
     await hass.async_block_till_done()
 
+    event_time = timestamp.replace(microsecond=0)
     assert len(events) == 2
     assert events[0].data == {
         "device_id": entry.device_id,
         "type": "camera_motion",
+        "timestamp": event_time,
     }
     assert events[1].data == {
         "device_id": entry.device_id,
         "type": "camera_person",
+        "timestamp": event_time,
     }