By agreement between employer and employee, a different day can replace a day that would be an NES public holiday, and a different part-day can replace a part-day public holiday. It is a facilitative provision listed in clause 7.2 for agreement with an individual, so it needs the individual employee's agreement rather than a workforce-wide direction.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.