Witness details on time to arrange rota (9)

I believe the answer is:

spectator

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'witness' is the definition.
(I know that witness can be written as spectator)

'details on time to arrange rota' is the wordplay.
'details on' becomes 'spec' (I can't justify this - if you can you should believe this answer much more).
'time' becomes 't' (abbreviation).
'to arrange' indicates anagramming the letters.
'rota' with letters rearranged gives 'ator'.
'spec'+'t'+'ator'='SPECTATOR'

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(Other definitions for spectator that I've seen before include "fan" , "given weekly inspection?" , "One watching a game" , "weekly magazine?" , "one's seen on the terraces?" .)

I've seen this clue in The Daily Express.

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