Mean to collect brief legal document towards the end of the day? (8)
I believe the answer is:
twilight
'towards the end of the day?' is the definition.
(twilight is a time of day)
'mean to collect brief legal document' is the wordplay.
'mean' becomes 'tight' (both can mean miserly).
'to collect' indicates putting letters inside (inserted letters are collected by others).
'brief' means to remove the last letter (a shorter or briefer version of the word).
'legal document' becomes 'will' (a will is a type of legal document).
'will' with its last letter taken off is 'wil'.
'tight' enclosing 'wil' is 'TWILIGHT'.
(Other definitions for twilight that I've seen before include "when the night's still young?" , "Vampire book" , "The time between day and night" , "Evening glow" , "Period just after sunset, becoming dark" .)