Yeah, I’m Canadian but that’s never stopped me from knowing everything about you yanks before. 
Is this a relatively new term?
Not really – it’s been in common use for at least ten years, probably more.
It’s been around since the 60s. A lot of people tend to use the term with the meaning of business sales spiking that day and the books finally going “into the black”. However, it appears that the Philadelphia PD was using the term in quite a different way.
I’ve heard about it since I was born. I’m 31.
I like the way the term is supposed to mean the point at which stores move decisively into the black for the year, when what it really means is a black day for anyone working retail, or possibly a black day for anyone trying to start their Christmas shopping, ideally without getting trampled.
While it’s been around, I don’t think it’s been used as pervasively by the media as it has been the last few years. The day seems to be referred to as such at absolutely every reference, when perhaps it would only be called that in reference to shopping forecasts 10 years ago, and only by trade insiders 20 years ago.
And in the last few years in Canada, it’s been mentioned in Canadian media with explanation that it derives from the US Thanksgiving holiday sales. Since Canadian Thanksgiving is in early October, this would otherwise be an unremarkable November work day and weekend.
I think there may be a sports-related meaning as well. I don’t follow spectator sports much, so I may be wrong.
ETA: if anything, I would have thought that Black Friday was the name for the day the market crashes…
This is how I see it, too. The financial reporter on the news might mention it, but nobody talked about it at Thanksgiving dinner, and it wasn’t named in stores’ circulars. Of course, when I was a kid retail Christmas didn’t start on Labor Day.
Well, I’ve heard about it for years and years and years, but I suspect I may be a bit more of a shopper than you are Leaffan. 
The Market Crash of 1929 was Black Tuesday.
As was the collapse of the wheat market in April of 1872.
Looking through the New York Times archives, there was a single reference to the Philadelphia PD’s usage in 1969. After that it doesn’t seem to have appeared until 1995, after which the phrase has been used regularly.
That roughly matches my memory. It seemed like in the mid-90s the phrase appeared out of nowhere and was suddenly everywhere.
It was the title of a Steely Dan song, from 1975.
I am not sure what the song is supposed to be about, however; probably not shopping after Thanksgiving (although it does mention removing “big red words form my little black book”). Some of the lyrics do seem to be invoking the stock market crash, but kangaroos are also involved, somehow. 
Interesting. Where’s the Times’s reference to that 1969 usage? (Did you spot something old – like, roughly contemporaneous with 1969 – in the Times’s archives or is it something fairly recent?)
The closely associated phrase is “Door Buster” sales, which of course are on Black Friday. “Door Buster” seems to be in every fuckin’ Christmas ad this year. Do they want people to riot in their stores?
These seasonal advertising slogans are getting on my nerves almost as much as Christmas carols.
If all the rioters buy high margin items, yes. Yes, we do
Is there an equivalent “big day” for shopping in Canada? I never thought much about it since the US had Thanksgiving 1 month right before Christmas.
What day(s) have the biggest sales there?
Boxing day sale is Dec 26th. All the stuff they couldn’t sell. This is why gift cards for Christmas (from me not to me) is an excellent idea. They can get so much more for the money on Boxing day.
Likewise, the Black Plague killed between 30% and 60% of Europe’s population between 1348 and 1350. All of these events are related as an unfortunate side effect of a concentrated human population with too few resources to support the overall supply chain. Sometimes, it is a rat infestation starting at the Silk road in Asia and moving into Europe as with the case of the Black Plague. Now it is a shortage of supercheap cheap LCD TV’s also coming from Asia being offered at Walmart for just a few hours at flea market prices. History tends to spawn common themes with predictable results.
I only heard that specific name within the past 5 years or so. I knew there were after-Thanksgiving sales, but they were generally called Day after Thanksgiving sales.
I’m not disagreeing that the term has existed, just that I didn’t see it used, and my family has never been into that stuff.