fix issue with daylight saving time change (#71)

* Improve setting the datetime for energy request

* Improve setting the datetime for gas request

* Add test for midnight value in CEST

* Change freeze_time from UTC to CET

* Change timezone notation for freeze_time

energyzero/energyzero.py

@@ -125,55 +125,56 @@ async def gas_prices(
         ------
             EnergyZeroNoDataError: No gas prices found for this period.
         """
-        start_date_utc: datetime
-        end_date_utc: datetime
-        utcnow: datetime = datetime.now(timezone.utc)
-        if utcnow.hour >= 5 and utcnow.hour <= 22:
-            # Set start_date to 05:00:00 and the end_date to 04:59:59 UTC next day
-            start_date_utc = datetime(
+        local_tz = datetime.now(timezone.utc).astimezone().tzinfo
+        now: datetime = datetime.now(tz=local_tz)
+
+        if now.hour >= 6 and now.hour <= 23:
+            # Set start_date to 06:00:00 and the end_date to 05:59:59 next day
+            # Convert to UTC time 04:00:00 and 03:59:59 next day
+            utc_start_date = datetime(
                 start_date.year,
                 start_date.month,
                 start_date.day,
-                5,
+                6,
                 0,
                 0,
-                tzinfo=timezone.utc,
-            )
-            end_date_utc = datetime(
+                tzinfo=local_tz,
+            ).astimezone(timezone.utc)
+            utc_end_date = datetime(
                 end_date.year,
                 end_date.month,
                 end_date.day,
-                4,
+                5,
                 59,
                 59,
-                tzinfo=timezone.utc,
-            ) + timedelta(days=1)
+                tzinfo=local_tz,
+            ).astimezone(timezone.utc) + timedelta(days=1)
         else:
-            # Set start_date to 05:00:00 prev day and the end_date to 04:59:59 UTC
-            start_date_utc = datetime(
+            # Set start_date to 06:00:00 prev day and the end_date to 05:59:59
+            # Convert to UTC time 04:00:00 prev day and 03:59:59 current day
+            utc_start_date = datetime(
                 start_date.year,
                 start_date.month,
                 start_date.day,
-                5,
+                6,
                 0,
                 0,
-                tzinfo=timezone.utc,
-            ) - timedelta(days=1)
-            end_date_utc = datetime(
+                tzinfo=local_tz,
+            ).astimezone(timezone.utc) - timedelta(days=1)
+            utc_end_date = datetime(
                 end_date.year,
                 end_date.month,
                 end_date.day,
-                4,
+                5,
                 59,
                 59,
-                tzinfo=timezone.utc,
-            )
-
+                tzinfo=local_tz,
+            ).astimezone(timezone.utc)
         data = await self._request(
             "energyprices",
             params={
-                "fromDate": start_date_utc.strftime("%Y-%m-%dT%H:%M:%S.000Z"),
-                "tillDate": end_date_utc.strftime("%Y-%m-%dT%H:%M:%S.999Z"),
+                "fromDate": utc_start_date.strftime("%Y-%m-%dT%H:%M:%S.000Z"),
+                "tillDate": utc_end_date.strftime("%Y-%m-%dT%H:%M:%S.999Z"),
                 "interval": interval,
                 "usageType": 3,
                 "inclBtw": self.incl_btw.lower(),
@@ -207,30 +208,31 @@ async def energy_prices(
         ------
             EnergyZeroNoDataError: No energy prices found for this period.
         """
-        # Set the start date to 23:00:00 previous day and the end date to 22:59:59 UTC
-        start_date_utc: datetime = datetime(
+        local_tz = datetime.now(timezone.utc).astimezone().tzinfo
+        # Set start_date to 00:00:00 and the end_date to 23:59:59 and convert to UTC
+        utc_start_date = datetime(
             start_date.year,
             start_date.month,
             start_date.day,
             0,
             0,
             0,
-            tzinfo=timezone.utc,
-        ) - timedelta(hours=1)
-        end_date_utc: datetime = datetime(
+            tzinfo=local_tz,
+        ).astimezone(timezone.utc)
+        utc_end_date = datetime(
             end_date.year,
             end_date.month,
             end_date.day,
-            22,
+            23,
             59,
             59,
-            tzinfo=timezone.utc,
-        )
+            tzinfo=local_tz,
+        ).astimezone(timezone.utc)
         data = await self._request(
             "energyprices",
             params={
-                "fromDate": start_date_utc.strftime("%Y-%m-%dT%H:%M:%S.000Z"),
-                "tillDate": end_date_utc.strftime("%Y-%m-%dT%H:%M:%S.999Z"),
+                "fromDate": utc_start_date.strftime("%Y-%m-%dT%H:%M:%S.000Z"),
+                "tillDate": utc_end_date.strftime("%Y-%m-%dT%H:%M:%S.999Z"),
                 "interval": interval,
                 "usageType": 1,
                 "inclBtw": self.incl_btw.lower(),

energyzero/models.py

@@ -23,7 +23,8 @@ def _timed_value(moment: datetime, prices: dict[datetime, float]) -> float | Non
     """
     value = None
     for timestamp, price in prices.items():
-        if timestamp <= moment < (timestamp + timedelta(hours=1)):
+        future_ts = timestamp + timedelta(hours=1)
+        if timestamp <= moment < future_ts:
             value = price
     return value
 

examples/energy.py

@@ -12,8 +12,8 @@ async def main() -> None:
     """Show example on fetching the energy prices from EnergyZero."""
     async with EnergyZero() as client:
         local = pytz.timezone("CET")
-        today = date(2023, 2, 8)
-        tomorrow = date(2023, 2, 9)
+        today = date(2023, 3, 29)
+        tomorrow = date(2023, 3, 29)
 
         energy_today = await client.energy_prices(start_date=today, end_date=today)
         energy_tomorrow = await client.energy_prices(

examples/gas.py

@@ -9,7 +9,7 @@
 async def main() -> None:
     """Show example on fetching the gas prices from EnergyZero."""
     async with EnergyZero() as client:
-        today = date(2023, 2, 8)
+        today = date(2023, 3, 28)
 
         gas_today = await client.gas_prices(start_date=today, end_date=today)
         print()

tests/fixtures/energy.json

@@ -1,5 +1,9 @@
 {
     "Prices": [
+        {
+            "price": 0.31,
+            "readingDate": "2022-12-06T22:00:00Z"
+        },
         {
             "price": 0.35,
             "readingDate": "2022-12-06T23:00:00Z"

tests/test_models.py

@@ -10,9 +10,9 @@
 from . import load_fixtures
 
 
-@pytest.mark.freeze_time("2022-12-07 14:00:00 UTC")
+@pytest.mark.freeze_time("2022-12-07 15:00:00+01:00")
 async def test_electricity_model(aresponses: ResponsesMockServer) -> None:
-    """Test the electricity model at 14:00:00 UTC."""
+    """Test the electricity model at 15:00:00 CET."""
     aresponses.add(
         "api.energyzero.nl",
         "/v1/energyprices",
@@ -76,6 +76,32 @@ async def test_electricity_none_date(aresponses: ResponsesMockServer) -> None:
         assert energy.average_price == 0.37
 
 
+@pytest.mark.freeze_time("2022-12-07 00:30:00+02:00")
+async def test_electricity_midnight_cest(aresponses: ResponsesMockServer) -> None:
+    """Test the electricity model between 00:00 and 01:00 with in CEST."""
+    aresponses.add(
+        "api.energyzero.nl",
+        "/v1/energyprices",
+        "GET",
+        aresponses.Response(
+            status=200,
+            headers={"Content-Type": "application/json"},
+            text=load_fixtures("energy.json"),
+        ),
+    )
+    async with ClientSession() as session:
+        today = date(2022, 12, 7)
+        client = EnergyZero(session=session)
+        energy: Electricity = await client.energy_prices(
+            start_date=today,
+            end_date=today,
+        )
+        assert energy is not None
+        assert isinstance(energy, Electricity)
+        # Price at 22:30:00 UTC
+        assert energy.current_price == 0.31
+
+
 async def test_no_electricity_data(aresponses: ResponsesMockServer) -> None:
     """Raise exception when there is no data."""
     aresponses.add(
@@ -95,9 +121,9 @@ async def test_no_electricity_data(aresponses: ResponsesMockServer) -> None:
             await client.energy_prices(start_date=today, end_date=today)
 
 
-@pytest.mark.freeze_time("2022-12-07 14:00:00 UTC")
+@pytest.mark.freeze_time("2022-12-07 15:00:00+01:00")
 async def test_gas_model(aresponses: ResponsesMockServer) -> None:
-    """Test the gas model at 14:00:00 UTC."""
+    """Test the gas model at 15:00:00 CET."""
     aresponses.add(
         "api.energyzero.nl",
         "/v1/energyprices",
@@ -123,9 +149,9 @@ async def test_gas_model(aresponses: ResponsesMockServer) -> None:
         assert gas.price_at_time(next_hour) == 1.47
 
 
-@pytest.mark.freeze_time("2022-12-07 03:00:00 UTC")
+@pytest.mark.freeze_time("2022-12-07 04:00:00+01:00")
 async def test_gas_morning_model(aresponses: ResponsesMockServer) -> None:
-    """Test the gas model in the morning at 03:00:00 UTC."""
+    """Test the gas model in the morning at 04:00:00 CET."""
     aresponses.add(
         "api.energyzero.nl",
         "/v1/energyprices",