Time of year closet is turned out (8)
I believe the answer is:
solstice
'time of year' is the definition.
'closet is turned out' is the wordplay.
'turned out' indicates anagramming the letters (turn out can mean to organise).
'closet'+'is'='closetis'
'closetis' with letters rearranged gives 'SOLSTICE'.
(Other definitions for solstice that I've seen before include "Closest I come to time when sun is farthest from equator" , "Shortest or longest day of the year" , "it occurs biannually" , "Time of highest or lowest noon sun" , "When the sun is farthest from the celestial equator" .)