code: def is_bday(date, bday=None):
      
      _date = Timestamp(date)
      if bday is None:
          bday = CustomBusinessDay(calendar=USFederalHolidayCalendar())
      return _date == (_date + bday) - bday
docs: Return true iff the given date is a business day.
  
      Parameters
      ----------
      date : :class:`pandas.Timestamp`
          Any value that can be converted to a pandas Timestamp--e.g.,
          '2012-05-01', dt.datetime(2012, 5, 1, 3)
  
      bday : :class:`pandas.tseries.offsets.CustomBusinessDay`
          Defaults to `CustomBusinessDay(calendar=USFederalHolidayCalendar())`.
          Pass this parameter in performance-sensitive contexts, such
          as when calling this function in a loop. The creation of the `CustomBusinessDay`
          object is the performance bottleneck of this function.
          Cf. `pandas.tseries.offsets.CustomBusinessDay
          <http://pandas.pydata.org/pandas-docs/stable/timeseries.html#custom-business-days-experimental>`_.
  
      Returns
      -------
      val : bool
          True iff `date` is a business day