Adjective

• 1. having no known beginning and presumably no end;

  "the dateless rise and fall of the tides"

  "time is endless"

  "sempiternal truth"

• 2. of such great duration as to preclude the possibility of being assigned a date;

  "dateless customs"

• 3. not bearing a date;

  "a dateless letter"

• 4. unaffected by time;

  "few characters are so dateless as Hamlet"

  "Helen's timeless beauty"