Maximum weekly hours and flexible working requests come from the NES (13.1). Day workers' ordinary hours are worked Monday to Friday inclusive, between 6.00 am and 6.00 pm. The usual start and finish times inside that spread can be changed only if the employer agrees it with the individual employee or with most of the employees concerned, and the spread itself may be altered for the whole workforce or a section of it by the same kind of agreement.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.