Sharepoint Calendar web part showing extra hours outside 'working hours'

[localzuk]

I am currently working on our 'Pupil' pages for sharepoint access, and have the Pupil Timetable showing almost how I want now. The only issue is the fact that even though I have working hours set to 9am - 4pm, it shows from 8am - 6pm.

 

How can I get it to stop showing the extra hours?