Practice management systems tend to treat a recurring task as having exactly one schedule. That works right up until two clients on the same service want the work on different days, which in payroll and bookkeeping is most of the time.
The usual workaround is to fork the service: Payroll (22nd), Payroll (25th), Payroll (Last Working Day). Now the same job exists three times over. Your service list fills with near-duplicates, reporting splits three ways, fee reviews have to be done three times, and a change to the checklist has to be made three times and will eventually be made twice.
The date a client wants their payroll run is not a different service. It is the same service on a different day, and that is all client schedules make it.

