Enable passing subdiv to holidays

- England now needs to be passed as country=UK, subdiv=England

timeserio/preprocessing/datetime.py

@@ -3,7 +3,7 @@
 import pandas as pd
 from sklearn.base import BaseEstimator, TransformerMixin
 from sklearn.utils.validation import check_is_fitted
-from typing import List, Union
+from typing import List, Union, Optional
 
 from .. import ini
 from .utils import _as_list_of_str, CallableMixin
@@ -52,7 +52,7 @@ def get_fractional_year_from_series(series: pd.Series) -> pd.Series:
 
 
 def get_is_holiday_from_series(
-    series: pd.Series, country: str = "UnitedKingdom"
+    series: pd.Series, country: str = "UnitedKingdom", subdiv: Optional[str] = None,
 ) -> pd.Series:
     """Return 1 if day is a public holiday.
 
@@ -61,7 +61,7 @@ def get_is_holiday_from_series(
     supported countries.
     """
     years = series.dt.year.unique()
-    holiday_dates = holidays.CountryHoliday(country, years=years)
+    holiday_dates = holidays.country_holidays(country, subdiv=subdiv, years=years)
     return series.dt.date.isin(holiday_dates).astype(int)