Whenever amenity is set out (7)
I believe the answer is:
anytime
'whenever' is the definition.
(thesaurus)
'amenity is set out' is the wordplay.
'is set out' is an anagram indicator.
'amenity' anagrammed gives 'ANYTIME'.
(Other definitions for anytime that I've seen before include "Whenever you like" , "At no particular moment" , "date not fixed" , "A tiny me (anag.)" , "At whatever moment" .)