Worker Adjustment and Retaining Notification Act states that:

Employers to give a 20 day notice before a layoff or facility closing involving more than 10 people

Employers to give a 40 day notice before a layoff or facility closing involving more than 30 people

Employers to give a 50 day notice before a layoff or facility closing involving more than 40 people

Employers to give a 60 day notice before a layoff or facility closing involving more than 50 people