This season appears to mark the end of Black Friday as we know it.

For decades, stores have opened their doors in the wee hours of the morning on the day after Thanksgiving known as Black Friday. But this year, that changed when major chains from Target to Toys R Us opened on Thanksgiving itself, turning the traditional busiest shopping day of the year into a two-day affair.

That means shoppers who wanted to fall into a turkey-induced slumber could still head out to stores early on Black Friday. Others could head straight from the dinner table to stores on Turkey Day. And stores were able to attract both groups by offering door-buster sales from $179 40-inch flat-screen TVs to $10 jeans at different times of the day.

Sam Chandler, 55, and his wife, Lori Chandler, 54, were part of the early group. By the time they reached the Wal-Mart in Greenville early Friday, they had already hit several stores, including Target and Best Buy. In fact, they had been shopping since midnight.

“We’ve learned over the years, you have to stand in line early and pray,” Sam said.

The earlier hours are an effort by stores to make shopping as convenient as possible for Americans, who they fear won’t spend freely during the two-month holiday season in November and December because of economic uncertainty. At the same time, Americans have grown more comfortable shopping on websites that offer cheap prices and the convenience of being able to buy something from smartphones, laptops and tablet computers from just about anywhere. That puts added pressure on brick-and-mortar stores — which can make up to 40 percent of their annual revenue during the holiday shopping season — to give consumers a compelling reason to leave their homes.

That’s becoming more difficult: the National Retail Federation, an industry trade group, estimates that overall sales in November and December will rise 4.1 percent this year to $586.1 billion, below last year’s 5.6 percent growth. But the online part of that is expected to rise 15 percent to $68.4 billion, according to Forrester Research.

In addition to expanding their hours, many also are offering free layaways and shipping, matching the cheaper prices of online rivals and updating their mobile shopping apps with more information.

“Every retailer wants to beat everyone else,” said C. Britt Beemer, chairman of America’s Research Group, a research firm based in Charleston. “Shoppers love it.”