When it comes to workplace attire, Casual Friday is out. And the hot new trend is Formal Friday where workers put away their jeans and hoodies – and wear their Sunday best, including dresses, suits and ties.

The trend is a backlash against workplaces that have become too casual where every day is Casual Friday. It’s especially true at tech companies, where the corporate uniform is typically dorm-room chic and includes jeans, sweats, Uggs, and PJ’s.

Fans of Formal Friday point out that Friday’s the best day of the week – so why not celebrate with a little style and grace? And you can see the trend in action everywhere from the New York digital marketing firm The Barbarian Group to a Peet's Coffee shop in San Francisco's Financial District where baristas wear bow ties and top hats on Fridays. Even Facebook is getting in on the action, where employees frequently dress up for what they call “Corporate Friday.”

And it could actually be good for business. Workplace etiquette expert Lydia Ramsey says that once young people are in the working world, it’s important to look like adults, not students who just pulled an all-nighter.  She also believes that employees are more productive when they dress more formally. And several studies back that up – showing that what people wear impacts their behavior.

Scientists have a name for it: They call "enclothed cognition" basically, the effects of clothing on the way we think. For example, people who put on a doctor's lab coat have an increased ability to pay attention, and make fewer mistakes.

But clothing also changes how others treat you - not just how you see yourself. For example, women who dress in a pantsuit during a job interview are more likely to be hired.  And a teaching assistant who wears formal clothes is perceived as more intelligent than one who dresses more casually. 

So Formal Fridays may just the thing you need if you're trying to get ahead.