Fix utility_meter on DST changes (#129862)

Co-authored-by: epenet <6771947+epenet@users.noreply.github.com>

homeassistant/components/utility_meter/manifest.json

@@ -8,5 +8,5 @@
   "iot_class": "local_push",
   "loggers": ["croniter"],
   "quality_scale": "internal",
-  "requirements": ["croniter==2.0.2"]
+  "requirements": ["cronsim==2.6"]
 }

homeassistant/components/utility_meter/sensor.py

@@ -9,7 +9,7 @@ from decimal import Decimal, DecimalException, InvalidOperation
 import logging
 from typing import Any, Self
 
-from croniter import croniter
+from cronsim import CronSim
 import voluptuous as vol
 
 from homeassistant.components.sensor import (
@@ -405,6 +405,16 @@ class UtilityMeterSensor(RestoreSensor):
         self._tariff = tariff
         self._tariff_entity = tariff_entity
         self._next_reset = None
+        self.scheduler = (
+            CronSim(
+                self._cron_pattern,
+                dt_util.now(
+                    dt_util.get_default_time_zone()
+                ),  # we need timezone for DST purposes (see issue #102984)
+            )
+            if self._cron_pattern
+            else None
+        )
 
     def start(self, attributes: Mapping[str, Any]) -> None:
         """Initialize unit and state upon source initial update."""
@@ -543,11 +553,10 @@ class UtilityMeterSensor(RestoreSensor):
 
     async def _program_reset(self):
         """Program the reset of the utility meter."""
-        if self._cron_pattern is not None:
-            tz = dt_util.get_default_time_zone()
-            self._next_reset = croniter(self._cron_pattern, dt_util.now(tz)).get_next(
-                datetime
-            )  # we need timezone for DST purposes (see issue #102984)
+        if self.scheduler:
+            self._next_reset = next(self.scheduler)
+
+            _LOGGER.debug("Next reset of %s is %s", self.entity_id, self._next_reset)
             self.async_on_remove(
                 async_track_point_in_time(
                     self.hass,

requirements_all.txt

@@ -702,7 +702,7 @@ connect-box==0.3.1
 construct==2.10.68
 
 # homeassistant.components.utility_meter
-croniter==2.0.2
+cronsim==2.6
 
 # homeassistant.components.crownstone
 crownstone-cloud==1.4.11

requirements_test_all.txt

@@ -598,7 +598,7 @@ colorthief==0.2.1
 construct==2.10.68
 
 # homeassistant.components.utility_meter
-croniter==2.0.2
+cronsim==2.6
 
 # homeassistant.components.crownstone
 crownstone-cloud==1.4.11

tests/components/utility_meter/test_sensor.py

@@ -1804,6 +1804,26 @@ async def test_self_reset_hourly_dst(hass: HomeAssistant) -> None:
     )
 
 
+async def test_self_reset_hourly_dst2(hass: HomeAssistant) -> None:
+    """Test weekly reset of meter in DST change conditions."""
+
+    hass.config.time_zone = "Europe/Berlin"
+    dt_util.set_default_time_zone(dt_util.get_time_zone(hass.config.time_zone))
+    await _test_self_reset(
+        hass, gen_config("daily"), "2024-10-26T23:59:00.000000+02:00"
+    )
+
+    state = hass.states.get("sensor.energy_bill")
+    last_reset = dt_util.parse_datetime("2024-10-27T00:00:00.000000+02:00")
+    assert (
+        dt_util.as_local(dt_util.parse_datetime(state.attributes.get("last_reset")))
+        == last_reset
+    )
+
+    next_reset = dt_util.parse_datetime("2024-10-28T00:00:00.000000+01:00").isoformat()
+    assert state.attributes.get("next_reset") == next_reset
+
+
 async def test_self_reset_daily(hass: HomeAssistant) -> None:
     """Test daily reset of meter."""
     await _test_self_reset(