Run Start of Year Process - field "Update as of"

Summary:

In the Payroll module when running the Start of Year Process what does the "Update as of" date field control in that job? The reason I'm asking is that in Indiana our county taxes go by where you live as of 01/01, this process looks at our employee's county of residence as of 01/01 to make sure we are taxing them correctly for calendar year 2024.

Our payroll cycles do not align with the 01/01 date so for the first check of 2024 (01/05/2024) it still taxes them on their previous county (pay period 12/17/2023-12/30/2023). Then by the 2nd check of the year it starts taxing them correctly; second pay period goes from 12/31/2023-01/13/2024.