"Calculate Seniority Dates" process parameter: Past Period in Days value?

Summary:

Hi All,

I was working on "Calculate Seniority Dates" process, which is scheduled to run every day. But had a question about the parameter: Past Period in Days. What should be its value if I need to increment seniority for all the employees by +1. As per the Oracle documentation:

Calculate Seniority Dates Process

But what if some Employee doesn't have any data changed will his or her seniority get incremented by 1 day after running this process. So, I added a generic large number for e.g.: 30000 and it worked, otherwise if the value is kept as 1, then quite a number of employee records do not get seniority date incremented by 1. Let me know if anyone knows the impact for doing it for 30000 days?