They don’t need a year to implement that. Just switch all your employees over to having 40 dependents for the tax holiday. There’s a bit of data processing to keep the old stuff around, but it’s not a year long implementation, unless the company is run by complete morons.
Remember Bush41 used an executive order to change the witholding tables..that was inplimented pretty quickly..this would be pretty much the same accounting procedure. You are correct, it can be done fairly quickly.
You haven't seen the stuff I have. I have been in IT for 30 years and there are systems older than me running still. Try to zero the tax tables and you will have div/0 errors all over the place.
Your "40 dependents" doesn't zero the tax -- and it messes with MOAs and the like that are based on after-tax figures.
Dependents represent withholding, not tax assessed.
Trust me, I know of what I speak. I have installed HR and Financial systems for some of the largest companies in the world, as well as some very large government entities.