More than 17 million people are expected to stay home from work Monday to recover from the Super Bowl.
It's known as "Super Sick Monday or the "Super Bowl Fever" for people who overdo it with food, alcohol and staying up too late watching the game.
The cost of productivity loss could top $4 billion, according to one employment firm.
And companies know full-well.
The staffing firm 'Office Team' found that 72 percent of H.R. managers thought the Monday after the Super Bowl should be a holiday.