code: def pub_date(soup):
      
      pub_date = first(raw_parser.pub_date(soup, date_type="pub"))
      if pub_date is None:
          pub_date = first(raw_parser.pub_date(soup, date_type="publication"))
      if pub_date is None:
          return None
      (day, month, year) = ymd(pub_date)
      return date_struct(year, month, day)
docs: Return the publishing date in struct format
      pub_date_date, pub_date_day, pub_date_month, pub_date_year, pub_date_timestamp
      Default date_type is pub