The day after Thanksgiving will be one of the busiest shopping days of the year, when millions of deal-hungry shoppers put down the turkey and stuffing to descend upon retail stores (and websites) looking for discounted TVs and toys. The longstanding post-Turkey Day tradition (which sometimes starts on Thanksgiving itself) marks the start of the holiday shopping season, but what gives with the dark, ominous moniker?

One common myth around the origins of the term “Black Friday” is that retailers coined the nickname as a reference to their own balance sheets. Companies that had been operating at a loss (“in the red”) the whole year could count on a massive shopping day on the fourth Friday of November to make them profitable for the year (“in the black”), thus “Black Friday.” However, that story may have been concocted by those same retailers in an effort to put a more positive spin on the busy shopping day. (Snopes.com also points to another widespread, but ultimately false, myth tracing the term’s origins back to the days of slavery.)

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Instead, the truth appears to point to a more derisive coining of the phrase. It is widely accepted now that the term “Black Friday” was first used in the early 1960s by exhausted Philadelphia police officers who had been besieged by tourists and shoppers flooding into the city on the day after Thanksgiving to get a jumpstart on Christmas shopping. In a 1994 article for The Philadelphia Inquirer, reporter Joseph Barrett wrote about his role in spreading the phrase while also giving the credit for coining it to the city’s traffic cops, many of whom were forced to work extra long shifts to deal with the masses of shoppers. After all, “black” is often used to describe a day filled with catastrophe (like a stock market crash, for instance).

Barrett also noted that marketers later tried changing the name to “Big Friday,” in another effort to paint a rosier picture of a shopping day that is, without a doubt, an important for retailers. But the term “Black Friday”—and it’s darkly humorous connotations—was the one that caught on and spread beyond Philadelphia over the ensuing years. It wasn’t until a couple of decades later that retailers across the country really started embracing the term as part of their annual post-Thanksgiving sales bonanzas.

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Today, Black Friday is still a massively important time of the year for U.S. retailers, though the creep of the Christmas shopping season and shoppers’ mass migration online has changed the name’s connotation somewhat. With marketers kicking off holiday sales earlier and earlier each year, many retailers now offer sales that start earlier in November and run well into December. And, in recent years, Black Friday hysteria has been muted by the growing influence of e-commerce in retail, with a large number of deals also available online, either for the unofficial holiday Cyber Monday, or even for advance Black Friday web sales from online giants like Amazon and Walmart that run throughout November—if not earlier.