Merge pull request #515 from openeemeter/fix/dst-date-range

Handle ambiguous and nonexistent local times

CHANGELOG.md

@@ -4,7 +4,7 @@ Changelog
 Development
 -----------
 
-* Placeholder
+* Handle ambiguous and nonexistent local times when creating daily dataclass
 
 4.0.6
 -----

eemeter/eemeter/models/daily/data.py

@@ -259,6 +259,8 @@ def _compute_meter_value_df(self, df: pd.DataFrame):
             end=end_date,
             freq="D",
             tz=df.index.tz,
+            ambiguous=True,
+            nonexistent="shift_forward",
         )
         all_days_df = pd.DataFrame(index=all_days_index)
         # the following drops common days to handle DST issues with pytz.

tests/daily_model/test_daily_data.py

@@ -24,6 +24,7 @@
 from eemeter.eemeter.samples import load_sample
 import numpy as np
 import pandas as pd
+from pandas import Timestamp, DatetimeIndex, DataFrame
 import pytest
 
 TEMPERATURE_SEED = 29
@@ -831,3 +832,23 @@ def test_offset_aggregations_hourly(il_electricity_cdd_hdd_hourly):
     )
     assert baseline is not None
     assert len(baseline.df) == NUM_DAYS_IN_YEAR
+
+
+def test_dst_handling():
+    # 2020-03-08 02:00 is nonexistent, should push to 03:00
+    tz = "America/New_York"
+    idx = DatetimeIndex([Timestamp("2020-03-07 02", tz=tz), Timestamp("2021-03-06 02", tz=tz)])
+    df = DataFrame({"observed": [1]*2, "temperature": [50]*2}, index=idx)
+    baseline = DailyBaselineData(df, is_electricity_data=True)
+    assert len(baseline.df) == 365
+    hours, counts = np.unique(baseline.df.index.hour, return_counts=True)
+    assert (hours == [2, 3]).all()
+    assert (counts == [364, 1]).all()
+
+    # 2020-11-01 01:00 is ambiguous, single index should be chosen
+    tz = "America/New_York"
+    idx = DatetimeIndex([Timestamp("2020-03-07 01", tz=tz), Timestamp("2021-03-06 01", tz=tz)])
+    df = DataFrame({"observed": [1]*2, "temperature": [50]*2}, index=idx)
+    baseline = DailyBaselineData(df, is_electricity_data=True)
+    assert len(baseline.df) == 365
+    assert (baseline.df.index.hour == 1).all()