For decades, Black Friday stood alone. The day after Thanksgiving marked the official start of the holiday shopping season, and was famous for “door buster” discounts on items like televisions and refrigerators designed to entice shoppers into stores. Then, in 2005, the National Retail Federation dreamed up another shopping idea—Cyber Monday—as an online rival to Black Friday. It wasn’t the busiest day for online retailers at first, but in time, helped by the offer of special deals, it became the biggest.

Now the two seem to be combining, as online retailers offer deals earlier and earlier in a trend some call “Black November.”

Black November got a kick-start a few years ago when Amazon began offering special discounts well before Thanksgiving. It continued this year with Amazon launching Black Friday discounts every five minutes starting the Friday before Thanksgiving, and with the world’s largest retailer, Walmart, offering the same deeply discounted deals online that shoppers can get in stores, such as a Samsung HD smart TV for $1,000 off.

While consumer spending in brick and mortar stores on Friday is expected to exceed 2015 numbers, online retail is predicted to grow even faster, says Jill Gonzalez, who tracks retail sales for Wallet Hub. “It’s generational. Going out to stores on Black Friday is less of a millennial mindset. It’s easier from a price comparison aspect to shop online. It’s knowing you got the best deal, it’s consumer empowerment,” says Gonzalez.

While Cyber Monday will indeed be the single biggest shopping day of the year online, the week before has become even bigger. Adobe Digital Insights predicts that $3.36 billion in sales will be made online next Monday, but also predicts that more than $5 billion will have already been rung up online on Thanksgiving day and Black Friday.

Not all retailers are following the trend. Mall giants like Sears and Macy’s are limiting many of their best Black Friday deals to in-person shoppers. And the online arms of some specialty shops like makeup retailer Sephora remain committed to Cyber Monday deals.

E-commerce remains just about 8 percent of all U.S. retail sales, according to Census Bureau statistics, but during the holidays more Americans shop online. According to Forrester Research analyst Susan Wu, online sales make up 16 percent of holiday shopping during the months of November and December, an expected $112 billion this year.