knocker-up

noun1

1. •
   (UK, historical) A person whose job was to go from house to house in the early morning and wake up workers by tapping on the bedroom window with a long pole or similarly convenient implement.

   • He [Driver Carruthers] started on the L.N.W.R. in 1907 as a knocker-up for four years, then became a cleaner, fireman, and finally a driver. — 1945