Day after today (8)
I believe the answer is:
tomorrow
'day after today' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tomorrow that I've seen before include "Manana to the Spanish" , "'..., and ..., and .../Creeps in this petty place from day to day/to the" , "___ Never Knows, 1966 Beatles song" , "The next day" , "It's another day" .)