Black Monday was the sell-off the day before the stock market crash of 1929, Black Tuesday. Black Wednesday was used to refer to a day of widespread air traffic snarls in 1954 as well as the day the British government was forced to withdraw a battered pound from the European Exchange Rate Mechanism in 1992. Black Thursday has variously been used for days of devastating brush fires, bombings and athletic defeats, among other unpleasantness.

So how is it that the term Black Friday has now come almost universally to denote joyous commercial excess, stupendous deals and big profits as the day when everyone heads out to shop for the holidays the day after Thanksgiving?

It wasn’t always this way. The New York Times first used the term Black Friday in an article in 1870 to refer to the day the gold market collapsed in September 1869.

Ben Zimmer, executive producer of Vocabulary.com, who has researched and written about the term, says its association with shopping the day after Thanksgiving began in Philadelphia in the 1960s — and even then the reference wasn’t positive. The local police took to calling the day after Thanksgiving Black Friday because they had to deal with bad traffic and other miseries connected to the throngs of shoppers heading for the stores that day.