Employees are entitled to a paid day off on a public holiday if it’s a day they would have otherwise worked on. If they work on that public holiday they’re paid at least time and a half for the time they work and get an alternative day off (if it is an otherwise working day for them).
The employee’s entitlement to be paid time and a half for working on a public holiday must be included in the employee’s employment agreement. The employment agreement could give the employee more than time and a half for the hours worked, for example, it might say double-time for working on a public holiday, but it can’t give the employee less than time and a half.
