As more stores open Thanksgiving Day, what happens to Black Friday?

Last year, Target made headlines when the store announced it would open on Thanksgiving Day. This year, even more retailers have opted to open their doors on Thursday instead of Friday, as the lure of holiday deals continue to creep earlier into holiday celebrations.

Black Friday, the unofficial start to the holiday shopping season, has been around since the early 1920s, although its name wasn't coined until the 1960s - giving reference to when retails would moved from the red (loss) into the black (profit). Holiday sales in November and December can account for 20 to 40 percent of a retailers annual sales, according to the National Retail Federation (NRF).

But now, dozens of national retailers have moved up their hours and are opening Thanksgiving Day, including Kohls, Toys R Us, Target, Wal-Mart, J.C. Penney and Macy's. Cedar Rapid's Lindale Mall and Williamsburg's Tanger Outlets are even opening on Thursday night.

"Everyone wants to push to make it longer," said Eugenio Aleman, a senior economist with Wells Fargo. "Retailers are trying to figure out how to outsmart their competitors."

But what does this mean for Black Friday? Is the blockbuster shopping day vulnerable to losing its No. 1 spot?

"Black Friday will continue to be the largest retail holiday," said Ron Prescott, a retail specialist with Iowa State University.

"We will have to see how much consumers want (shopping) to encroach (on Thanksgiving) - that will determine how early retailers will open," he said.

• See also: Black Friday Live

This year's short holiday shopping season is also contributing to the slew of retailers opening on Thursday.

"There's a weird thing happening this year because we're losing one week between Thanksgiving and Christmas," Aleman said. "So everyone is trying to rearrange their schedules to accommodate as many customers as possible."

Fewer consumers are expected to shop this weekend,  according to the NRF, with about 140 million shoppers overall. Black Friday will still bring out the most shoppers by far, about 97 million, and another 33 million people expected to shop on Thanksgiving.

Last year,  247 million people shopped Thanksgiving weekend, including 89 million shoppers on Black Friday and 35 million on Thanksgiving.

Shoppers are also planning to spend less this holiday season. According to the NRF's annual holiday consumer spending survey, the average holiday shopper will spend $737.95 on gifts, decor and greeting cards this year, which is about 2 percent less than the $752.24 they spent last year.

Laura Smarandescu, an assistant marketing professor at Iowa State, said traditional Black Friday shopping attracts a certain type of consumer, who will continue to come out year after year for the deals.

"Not every one wants to shop at midnight or at 5 a.m. and deal with the crowd and the rushing," she said. "They expect the deals to be better on Friday, so those shopper will still go out."