Macy's Inc is planning its earliest start ever to the holiday shopping season by opening many of its U.S. stores at midnight on Thanksgiving night.

Target Corp announced a similar move last week, setting the stage for what is likely to be a competitive holiday season for U.S. store chains, with analysts and economists expecting only modest sales gains this year.

The National Retail Federation earlier this month forecast that U.S. retail sales would rise 2.8 percent in November and December, excluding cars, gas, and restaurants.

The fight for sales is likely to be more intense this year for chains that cater to middle-income shoppers who are ready to spend more, but will still be careful with their money, raising the stakes for a good start to the season for discount retailers and department stores.

We expect significant competition in the moderate market and in electronics, Richard Hastings, a Global Hunter Securities analyst said, noting that it costs little to keep stores open a few more hours.

While store hours can vary by chain and by location, most chains opened their doors at 3 a.m. or 4 a.m. on the day after Thanksgiving last year.

But opening times have gotten earlier and earlier in recent years, inevitably leading to midnight openings.

Last year, the NRF found that the number of people who began their Black Friday shopping at midnight had tripled to 9.5 percent of shoppers.

Shoppers are often lined up outside stores, particularly electronics retailers such as Best Buy , at midnight even if the stores opened just a few hours later. Last year, Best Buy stores opened their doors at 5 a.m.

Other chains that last year opened doors at midnight include video-games chain GameStop and Wal-Mart Stores Inc .

Wal-Mart opened many of its U.S. discount stores on Thanksgiving Day in 2010 and kept them open overnight, a tactic it adopted after an employee was trampled to death three years ago on Black Friday.

Black Friday is a term co-opted by retailers to refer to the time of year when their business moves into the black, or turns a profit. This year, the event will be about keeping sales momentum that has picked up in recent months.

(Reporting by Phil Wahba; Editing by Lisa Von Ahn and Maureen Bavdek)

Target