class_docstr: Defines an array of dates specified by a regular schedule.
code: def holiday_calendar(self):
      return self._holiday_calendar
  
imports: import tensorflow.compat.v2
  from tf_quant_finance.datetime import constants
  from tf_quant_finance.datetime import date_tensor
label_desc: Use image node_id 6 for calling the PeriodicSchedule obj's underlying member method code with example usage: obj.holiday_calendar() and returns: self