docs: def convert_date(d, custom_date_string=None, fallback=None):
          """
          for whatever reason, sometimes WP XML has unintelligible
          datetime strings for pubDate.
          In this case default to custom_date_string or today
          Use fallback in case a secondary date string is available.
  
          Incidentally, somehow the string 'Mon, 30 Nov -0001 00:00:00 +0000'
          shows up.
          >>> xp = XML_parser
          >>> xp.convert_date("Mon, 30 Mar 2015 11:11:11 +0000")
          '2015-03-30'
          """
          if d == 'Mon, 30 Nov -0001 00:00:00 +0000' and fallback:
              d = fallback
          try:
              date = time.strftime("%Y-%m-%d", time.strptime(d, '%a, %d %b %Y %H:%M:%S %z'))
          except ValueError:
              date = time.strftime("%Y-%m-%d", time.strptime(d, '%Y-%m-%d %H:%M:%S'))
          except ValueError:
              date = custom_date_string or datetime.datetime.today().strftime("%Y-%m-%d")
          return date