Rallies around a year later (7)
I believe the answer is:
someday
'later' is the definition.
(some day in the future)
'rallies around a year' is the wordplay.
'rallies' becomes 'demos' (demonstrations).
'around' says the letters should be written backwards.
'year' becomes 'y'.
'demos' reversed gives 'somed'.
'somed'+'a'+'y'='SOMEDAY'
(Other definitions for someday that I've seen before include "At a future time; samoyed (anag.)" , "When will my prince come" , "eventually" , "song" , "An unspecified time in the future" .)