Hi sales68
It is not possible to track/calculate the amount of holiday leave with the standard online payroll.
You can however add holiday pay to your employees payslip, click into the employees details, select the green plus icon at the bottom of the page, select additional pay, select the white + icon in the top right hand corner of the screen, select add/Other earnings, in the Name box enter Holiday Pay, in the default amount either enter the amount you would like to pay the employee or enter zero, save. If you enter zero when you run the payroll it will allow you to enter an amount.