Schedule setback for alternates (7)
I believe the answer is:
rotates
'alternates' is the definition.
(rotating is a kind of alternating)
'schedule setback' is the wordplay.
'schedule' becomes 'rota' (a rota is a schedule).
'setback' becomes 'tes' (I've seen this in other clues).
'rota'+'tes'='ROTATES'
'for' acts as a link.
(Other definitions for rotates that I've seen before include "Goes round" , "Turns round" , "Turns around an axis" , "Takes turns" , "revolves" .)