class_docstr: Class that defines a holiday with start/end dates and rules
  for observance.
class_docstr_tok: ["Class","that","defines","a","holiday","with","start\/end","dates","and","rules","for","observance","."]
docstr: Get reference dates for the holiday.
  
  Return reference dates for the holiday also returning the year
  prior to the start_date and year following the end_date.  This ensures
  that any offsets to be applied will yield the holidays within
  the passed in dates.
docstr_tok: ["Get","reference","dates","for","the","holiday",".","Return","reference","dates","for","the","holiday","also","returning","the","year","prior","to","the","start_date","and","year","following","the","end_date",".","This","ensures","that","any","offsets","to","be","applied","will","yield","the","holidays","within","the","passed","in","dates","."]
code: def _reference_dates(self, start_date, end_date):
      """
      Get reference dates for the holiday.
  
      Return reference dates for the holiday also returning the year
      prior to the start_date and year following the end_date.  This ensures
      that any offsets to be applied will yield the holidays within
      the passed in dates.
      """
      if self.start_date is not None:
          start_date = self.start_date.tz_localize(start_date.tz)
  
      if self.end_date is not None:
          end_date = self.end_date.tz_localize(start_date.tz)
  
      year_offset = DateOffset(years=1)
      reference_start_date = Timestamp(
          datetime(start_date.year - 1, self.month, self.day)
      )
  
      reference_end_date = Timestamp(
          datetime(end_date.year + 1, self.month, self.day)
      )
      # Don't process unnecessary holidays
      dates = date_range(
          start=reference_start_date,
          end=reference_end_date,
          freq=year_offset,
          tz=start_date.tz,
      )
  
      return dates
  
imports: from datetime import datetime, timedelta
  import warnings
  from dateutil.relativedelta import FR, MO, SA, SU, TH, TU, WE
  import numpy
  from pandas.compat import add_metaclass
  from pandas.errors import PerformanceWarning
  from pandas import DateOffset, Series, Timestamp, date_range
  from pandas.tseries.offsets import Day, Easter
label_desc: Use image node_id 4 for calling the Holiday obj's underlying member method code with example usage: obj._reference_dates(start_date, end_date) and returns: dates