Timecards are used to capture exceptions.  Earnings/Deductions will need to be on the employee's payroll page in order from them to be used in a timecard.  You can globally add an earning to employees in the payroll task "Assign Earnings/Deductions".  Once the codes are on the employee payroll page and have proper start/stop dates and set to calculate yes, you can create a timecard with PTO for one employee and then copy that timecard.  On the Timecard List, click the Copy button.  You can assign the timecard by employee number, class code, or a selection list to create timecards.

As an alternative - if everyone is getting 8 hours of holiday pay, you can go into Payroll - Processes - Update Earnings/Deductions, select the code, replace the Default Hours to 8.00.  Update by 'Set Criteria" and set your criteria so that the Employment Status = Active. These hours will not show on the timecards, but will be part of the processing.  Check the pre-processing register carefully.  You will need to make sure that anyone who doesn't get vacation pay has an entry on their timecard that overrides the amount to 0.00.  Once payroll has been completed, you must remember to go back and update the default hours to 0.00.