A date Kevin fixed after end of spring to make mutual concessions (4,3,4)
I believe the answer is:
give and take
'mutual concessions' is the definition.
(I've seen this before)
'a date kevin fixed after end of spring' is the wordplay.
'fixed' is an anagram indicator.
'after' says to put letters next to each other.
'end of' says to take the final letters.
The last letter of 'spring' is 'g'.
'a'+'date'+'kevin'='adatekevin'
'adatekevin' is an anagram of 'iveandtake'.
'iveandtake' put after 'g' is 'GIVE-AND-TAKE'.
'to make' is the link.
(Other definitions for give and take that I've seen before include "Swap" , "Compromise, mutual conceding" , "accommodation" , "exchange" , "Mutual concessions and compromises" .)