Day came for reforming educational institution (7)
I believe the answer is:
academy
'educational institution' is the definition.
(academy is a kind of educational institution)
'day came for reforming' is the wordplay.
'for reforming' indicates an anagram (I've seen 'for reform' mean this (I've seen this in other clues)).
'day'+'came'='daycame'
'daycame' with letters rearranged gives 'ACADEMY'.
(Other definitions for academy that I've seen before include "Specialised educational establishment" , "Centre of learning" , "Institution for the advancement of art, science, literature" , "Type of school" , "Teaching establishment" .)