Decreed a raid should be carried out by, one day (8)
I believe the answer is:
ordained
'decreed' is the definition.
(I know that decreed can be written as ordained)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for ordained that I've seen before include "Decreed, or appointed to priesthood" , "Laid down the law" , "Conferred holy orders on" , "Like a priest" , "Elevated to the priesthood" .)