Open English Wordnet
Adjectives
(s)dateless, endless, sempiternalhaving no known beginning and presumably no end“the dateless rise and fall of the tides”,
“time is endless”,
“sempiternal truth” (s)datelessof such great duration as to preclude the possibility of being assigned a date“dateless customs” (s)dateless, timelessunaffected by time“few characters are so dateless as Hamlet”,
“Helen's timeless beauty”