Like it or loathe it, you can't ignore it: Black Friday, the US-inspired shopping rampage, lands on 27 November 2015.
John Lennon once said that The Beatles were bigger than Jesus; we wouldn't be so blasphemous, but in purely financial terms Black Friday is definitely bigger than Christmas.
Analysts are predicting that British shoppers alone will spend up to £1bn on tech, games, clothes and other goods in 24 hours.
As much as £3.5bn is expected to be spent in the during that whole weekend, which ends with Cyber Monday on November 30. It's even bigger in America, where Black Friday is much more established.
Here's why Black Friday is bigger than Christmas:
It's when everybody spends their money
Cyber Monday, the Monday immediately after Black Friday, used to be the biggest internet shopping day of the year.
That's changed somewhat, especially now so many employers take a dim view of people using work PCs to do their Christmas shopping, but a poll of shoppers in the UK, US, Canada, New Zealand and Australia by analytics firm SAS found that shoppers expected to do most of their discount shopping this week, not the week before Christmas.
29% said Black Friday week was their favourite shopping time, with 28% and 26% nominating Black Friday and Cyber Monday alone; by comparison, the week before Christmas polled at 23% and Christmas Eve just 5%.
The same survey found 75% of UK shoppers say that price is the single most important factor in their gift-buying, with 51% saying that getting a bargain is really important.
Those factors are particularly important among 25 to 29-year-olds, who are most likely to compare online prices and shop around. For that group, Black Friday is a really big deal.
You can be sure your gifts will turn up on time
If you're shopping for others, Black Friday happens early enough in the calendar that you can be 99% sure that what you buy will be delivered long before Santa starts stuffing his sack.
Good luck getting fast delivery on anything you order during Christmas week.
You're not stuffed if something sells out
It's two days before Christmas and you're trying and failing to find this year's must-have present, toy or Heston pudding from Waitrose.
You try and try, but nobody's going to restock this side of Rudolph's big night out.
On Black Friday, on the other hand, there's a very good chance that if Brilliant Deal X sells out on retailer Y, one of its rivals will have Almost As Brilliant Deal Z available for a last-minute change of plan.
You're less likely to get punched
With some retailers opting out of Black Friday this year, chances are that in the UK at least we won't see a repeat of last year's awful scenes where supposed grown-ups scrapped over heavily discounted, not-that-brilliant flat screen TVs.
That and the ease of doing everything online means that Black Friday 2015 is much more pleasant and less bad-tempered than a department store on Christmas Eve.
It can suck the cash out of Christmas
Home Retail Group, owner of Argos and Homebase, suffered a share price fall when it turned out that its Christmas 2014 sales weren't brilliant; consumers splurged on its Black Friday deals but didn't come back before Santa came.
Other retailers reported similarly disappointing Christmas trading figures. As the Guardian put it, Black Friday "wreaked havoc on the high street and hit shops' profits in the run-up to Christmas."
Retailers need to get it right first time
Retailers that do a bad job on Black Friday face a tough response from shoppers. According to SAS, our tolerance for bargains is limited to one minute for each one percent discount when waiting for a store to open, and 40 seconds at the checkout.
Long queues, online or offline, mean abandoned shopping carts.
It can make or break a company on the stock market
Poor performance doesn't just mean abandoned shopping carts. It can mean a drop in retailers' share prices too.
Home Retail Group wasn't the only firm battered by the stock market over its Black Friday performance: many analysts use Black Friday as a way to predict whether the retail sector will have a good or bad Christmas, and they adjust their valuation of firms' shares accordingly.
Those valuations are adjusted not just on the basis of the big picture, but on individual firms' performance: if the markets think they performed badly on Black Friday, it shakes their optimism for the rest of the shopping period.
The market changes tend to be fairly short term - Wall Street traders won't be hurling themselves out of windows if Best Buy doesn't do quite as well as expected - but they're still significant.
Main image credit: John Jones / Flickr