(ABC News) -- Kmart should be ashamed for airing its first holiday commercial some 100 days before Christmas when temperatures topped 90 degrees in much of the country, some shoppers say.
"I do not want to see Christmas ads when it is still SUMMER," wrote a customer on Kmart's Facebook page. "I will not be shopping at Kmart this year due to your advertising this early, I don't care what the reason."
Kmart, a unit of Sears, is defending the timing of the new ad, saying it aired early to announce the rollout of a new promotion that began Sept. 8.
In a statement to ABC News, Kmart said, "Customers can plan in advance in order to take advantage of layaway for holiday purchases."
Another Facebook user told Kmart, "There is no reason to make the holidays into a consumer nightmare. You should be ashamed."
Retailers are gearing up for the holiday selling season, when many companies ring up 20 percent of the year's sales.
"The time between Thanksgiving and Christmas is the shortest it can ever be on retail selling days. [Retailers] have to start earlier," said Jan Kniffen, retail analyst and CEO of J Rogers Kniffen Worldwide Enterprises.
Kmart isn't the only retailer marketing holiday promotions.
On Aug. 22, Walmart announced plans to launch free layaway from Sept. 13 through Dec. 13, officially kicking off the start to the holiday season. Walmart's Facebook fans received a two-day head start on layaway from Thursday through Friday.
Last Fall, Target ran its first holiday advertisement on Oct. 7, while Black Friday sales are beginning earlier and earlier each year.
Whether the chicken or the egg came first, the marketing blitz may be working. The National Retail Federation says more than 40 percent of holiday shoppers start buying before Halloween.
The best bargains, though, come after the holidays.
Online discount personal shopper ShopitToMe analyzed 585,000 markdowns from over 150 online shopping sites through 2012. February is the best time to buy online, with President's Day discounts averaging around 48 percent.