Can I set up an hour benefit to calculate at time-and-a-half or double time?

Additional hour benefits cannot calculate at a rate other than the employee's regular rate of pay.

However, if you need to pay an employee double time (as is often required in California), the double time rate can be entered in the 
Other Rate field on the employee's Wage Record in Payroll. You can then enter their hours under the Standard Hour Benefit Type called Other.