Periods when shock is reported (4)
I believe the answer is:
days
'periods' is the definition.
(I've seen this before)
'shock is reported' is the wordplay.
'shock' becomes 'daze' (synonyms).
'is reported' shows a homophone (sound like).
'daze' is a homophone of 'DAYS'.
'when' is the link.
(Other definitions for days that I've seen before include "Periods (of week)" , "See 7 and 18" , "Time period(s)" , "Sun, Mon, Tues, ..." , "` `They are not long, the .... of wine and roses' ' (Dowson)" .)