You must receive a written notice 60 days before the date of a mass layoff or plant closing if you meet the conditions discussed in this brochure. If your employer does not give you the required notice, you may be able to seek damages for back pay and benefits for up to 60 days, depending on how many days’ notice you actually received.
https://www.dol.gov/sites/dolgov/files/ETA/Layoff/pdfs/WorkerWARN2003.pdf