A weekly rest day is important for an employee’s well-being. Your employer can only require you to work on your rest day under exceptional circumstances.
Rest day pay is set at a higher rate to compensate employees for the extra hours worked. Your employer cannot give you time off instead of rest day pay if they ask you to work on a rest day, if you are covered under Part IV of the Employment Act.
If you are not covered under Part IV, the entitlement would depend on what is in your employment contract.