code: def _parse_gmt_time(timestring):
      
      # Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 822, updated by RFC 1123
      try:
          return time.strptime(timestring, "%a, %d %b %Y %H:%M:%S GMT")
      except Exception:
          pass
  
      # Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
      try:
          return time.strptime(timestring, "%A %d-%b-%y %H:%M:%S GMT")
      except Exception:
          pass
  
      # Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format
      try:
          return time.strptime(timestring, "%a %b %d %H:%M:%S %Y")
      except Exception:
          pass
  
      # Sun Nov  6 08:49:37 1994 +0100      ; ANSI C's asctime() format with
      # timezon
      try:
          return parsedate(timestring)
      except Exception:
          pass
  
      return None
docs: Return a standard time tuple (see time and calendar), for a date/time string.