NEW YORK (AP) -- Toy shoppers can forget about relaxing after a big Thanksgiving meal.

Toys R Us is pushing back its opening time for the fifth year in a row, opening doors at 5 p.m. nationwide on Nov. 28, Thanksgiving Day, three hours before its 8 p.m. opening last year.

Traditionally, the Friday after Thanksgiving, known as Black Friday, is one of the biggest shopping days of the year as retailers open up in early morning hours and Americans gear up for the holiday season. But over the past several years retailers ranging from Toys R Us to Macy's have pushed opening times earlier and earlier into Thanksgiving itself. This year, Macy's, J.C. Penney, Kohl's and others have announced opening hours on Thanksgiving evening.

The retailers say it's what customers want, but they are also trying to grab as many dollars as they can during the key holiday season, which can account for anywhere from 20% to 40% of annual revenue. Even as the U.S. job and housing markets improve, shoppers have scaled back because they are uncertain about the future.

There's also more pressure on retailers this year because the period between Thanksgiving and Christmas is six days shorter than in 2012.

Overall, The National Retail Federation, the nation's largest retail trade group, expects an increase of 3.9% in sales for the November-December period, up from 3.5% last year.

Privately held Toys R Us is offering a bounty of doorbuster specials to lure customers in on Thanksgiving, from 5 p.m. to 9 p.m., while supplies last.