Tax modifier effective a particular date: UMOD

We need to change a tax modifier for a certain group of employees effective a date. The payroll should default to the old configuration (Tax modifier) for retroactive pay periods prior to a given date and use the new tax modifier for payments made after a specified date.

Issue: If we use the CMPER to compare the payroll periods, the offcycle payrolls are not detected. We need a way to detect paydate of a payroll so that we can compare against the cutoff date and enable the new rule effective that date.Using the constant table also does not work since it compares the payroll run date of the payroll.