Use native datetime value in MQTT sensors (#59923)

homeassistant/components/mqtt/sensor.py

@@ -21,6 +21,8 @@ from homeassistant.const import (
     CONF_NAME,
     CONF_UNIT_OF_MEASUREMENT,
     CONF_VALUE_TEMPLATE,
+    DEVICE_CLASS_DATE,
+    DEVICE_CLASS_TIMESTAMP,
 )
 from homeassistant.core import HomeAssistant, callback
 import homeassistant.helpers.config_validation as cv
@@ -196,6 +198,18 @@ class MqttSensor(MqttEntity, SensorEntity):
                     self._state,
                     variables=variables,
                 )
+
+            if payload is not None and self.device_class in (
+                DEVICE_CLASS_DATE,
+                DEVICE_CLASS_TIMESTAMP,
+            ):
+                if (payload := dt_util.parse_datetime(payload)) is None:
+                    _LOGGER.warning(
+                        "Invalid state message '%s' from '%s'", msg.payload, msg.topic
+                    )
+                elif self.device_class == DEVICE_CLASS_DATE:
+                    payload = payload.date()
+
             self._state = payload
 
         def _update_last_reset(msg):

tests/components/mqtt/test_sensor.py

@@ -8,7 +8,7 @@ import pytest
 
 from homeassistant.components.mqtt.sensor import MQTT_SENSOR_ATTRIBUTES_BLOCKED
 import homeassistant.components.sensor as sensor
-from homeassistant.const import EVENT_STATE_CHANGED, STATE_UNAVAILABLE
+from homeassistant.const import EVENT_STATE_CHANGED, STATE_UNAVAILABLE, STATE_UNKNOWN
 import homeassistant.core as ha
 from homeassistant.helpers import device_registry as dr
 from homeassistant.setup import async_setup_component
@@ -80,6 +80,58 @@ async def test_setting_sensor_value_via_mqtt_message(hass, mqtt_mock):
     assert state.attributes.get("unit_of_measurement") == "fav unit"
 
 
+@pytest.mark.parametrize(
+    "device_class,native_value,state_value,log",
+    [
+        (sensor.DEVICE_CLASS_DATE, "2021-11-18", "2021-11-18", False),
+        (sensor.DEVICE_CLASS_DATE, "invalid", STATE_UNKNOWN, True),
+        (
+            sensor.DEVICE_CLASS_TIMESTAMP,
+            "2021-11-18T20:25:00+00:00",
+            "2021-11-18T20:25:00+00:00",
+            False,
+        ),
+        (
+            sensor.DEVICE_CLASS_TIMESTAMP,
+            "2021-11-18 20:25:00+00:00",
+            "2021-11-18T20:25:00+00:00",
+            False,
+        ),
+        (
+            sensor.DEVICE_CLASS_TIMESTAMP,
+            "2021-11-18 20:25:00+01:00",
+            "2021-11-18T19:25:00+00:00",
+            False,
+        ),
+        (sensor.DEVICE_CLASS_TIMESTAMP, "invalid", STATE_UNKNOWN, True),
+    ],
+)
+async def test_setting_sensor_native_value_handling_via_mqtt_message(
+    hass, mqtt_mock, caplog, device_class, native_value, state_value, log
+):
+    """Test the setting of the value via MQTT."""
+    assert await async_setup_component(
+        hass,
+        sensor.DOMAIN,
+        {
+            sensor.DOMAIN: {
+                "platform": "mqtt",
+                "name": "test",
+                "state_topic": "test-topic",
+                "device_class": device_class,
+            }
+        },
+    )
+    await hass.async_block_till_done()
+
+    async_fire_mqtt_message(hass, "test-topic", native_value)
+    state = hass.states.get("sensor.test")
+
+    assert state.state == state_value
+    assert state.attributes.get("device_class") == device_class
+    assert log == ("Invalid state message" in caplog.text)
+
+
 async def test_setting_sensor_value_expires_availability_topic(hass, mqtt_mock, caplog):
     """Test the expiration of the value."""
     assert await async_setup_component(