docs: def quarter_boundaries(quarter):
      """Returns first and last day of a quarter
  
      Args:
          quarter (str) quarter, in format '2015Q1'
  
      Returns: (tuple) datetime.dates for the first and last days of the quarter
      """
      year, quarter = quarter.split('Q')
      year = int(year)
      quarter = int(quarter)
      first_month_of_quarter = 3 * quarter - 2
      last_month_of_quarter = 3 * quarter
      first_day = date(year, first_month_of_quarter, 1)
      last_day = date(year, last_month_of_quarter, monthrange(year, last_month_of_quarter)[1])
      return first_day, last_day