Clipper's No 1 record-keeper has day off (9)
I believe the answer is:
topiarist
'clipper's' is the definition.
(a topiarist clips hedges)
I can't explain the rest of the clue.
(Other definitions for topiarist that I've seen before include "One who can produce sculpture" , "One who shapes shrubs ornamentally" , "Gardener" , "Bush trimmer" .)