Super Bowl Sunday is one of the biggest parties of the year.

The morning after, however, is not nearly as fun. For those football fans who may have over-imbibed  last night, today is going to be a rough workday. That's assuming they even show up. A whopping 4.4 million will straggle in late, according to a study conducted by the Workforce Institute at Kronos, and 1.5 million won’t even bother. They’ll call in “sick.”

All in all, the post-party haze will cost U.S. businesses an estimated $820 million in lost productivity, according to HR site TLNT. That statistic, and the prospect of sleeping in after a big night out, has inspired 10,000 Americans to sign a petition to make the Monday after the Super Bowl a national holiday. If the petition reaches 100,000 signatures, the Obama administration will have to formally respond.

"I am running on the assumption that the day after the Super Bowl is one of the least productive days of the work year, along with the day before Christmas and New Year's Eve," said Josh Moore, who launched the petition and owns the fantasy football website 4for4, to Business News Daily. "Having that day off would not make the workforce lose too much productivity.”

In the meantime, business owners are just going to have to make the most of a slightly groggy workforce. Here are some tips on how to handle employees dealing with the Super Bowl Monday blues.

Have plenty of anti-hangover supplies on hand. A big chunk of hangover pain comes from dehydration, so loading up on water, sports drinks, or fruit juice can go a long way. Ibuprofen will help kick those nagging headaches, so that your employees will actually be able to think about work, and a little sugar and caffeine can’t hurt. “Embrace it with extra coffee and pastries on hand,” advised Jessica Herrin, founder and CEO of San Francisco-based jewelry and accessory site Stella & Dot. “After all, it's not every day your team goes all the way. Go Niners!”

Have a personal conversation with a struggling employee. Let him or her know that their behavior isn’t going unnoticed, but you still expect the job to be done. “I will ask them why they are feeling down and let them know that their behavior and appearance is noticeable,” said Tiffanie Hartenstein, operations manager at Advanced Automative Concepts near New Orleans, home of Super Bowl XLVII and Mardi Gras celebrations. “Our hope is that once we have brought this to their attention they will make an extra effort to get back on track.”

Consider being more flexible with your start time, or turn employees loose if they’re just too fuzzy to function. As long as employees don't make it a habit of showing up at work hungover, it might be a good idea to be a little forgiving. Tell them to go home, rest, and that you expect them to come in the next day fully recharged. Odds are this will make enough of a lasting impression that you won’t see the problem crop up again. “For us the way it works best is for everyone to be very autonomous.,” said Sarah Windham, a PR rep for M-Edge, a company outside Baltimore that makes protective covers for tablets, e-readers, and a range of electronic devices. “It's a personal responsibility thing, not like a clock in clock out, are you going to be here or not.” When employees feel responsible for their own work and love what they do, she said, that helps keeps them motivated and on track.

"We’re so thrilled to be in the Super Bowl after 13 years," she added. "But I’m sure there will be along line at the coffee on Monday."