The 12 days of Christmas may be the favorite ones of holiday carolers, but it's only the next four that matter now to retailers.

The crucial retail season that ends Tuesday has been characterized since Thanksgiving by sluggish consumer spending, but merchants are hoping for an avalanche of shopping on the long weekend before Christmas.

They hope the calendar will help boost their sales. Most people here and nationwide are off work for the holiday starting today -- the first time there have been so many consecutive free shopping days before Christmas since the beginning of the 1980s.

"I think a lot of people have waited, looking but not buying and figuring they had that extra time, since sales have been so spotty," said Ben Kovalsky, president of Cosmetic and Fragrance Concepts Inc., parent company of the 34-store discount Cosmetic Center chain. "We are looking for all hell to break loose."

It may be breaking already. "The sales have been building for 12 consecutive days and we expect them to peak on Christmas Eve morning," said Don Uselmann, general manager of Saks Fifth Avenue in Chevy Chase.

"It should be a huge weekend with monstrous sales," said Howard Applebaum, vice president of the 33-store Kemp Mill Music chain. "There is a pent-up demand out there and it's just waiting to blow."

Although Applebaum said sales at the retail music chain have been solid this year, he is estimating that 26 percent of this month's business will be done in the next few days. Other retailers are predicting similar sales volume.

Most years, consumers wait until the last minute to buy. Last year, for example, one poll showed that nearly 20 percent of shoppers did not buy until Christmas Eve. But retailers in Washington are hoping their aggressive discounting -- from 20 percent to 50 percent on average -- over the past few weeks will spur customers to buy a little sooner.

"Retailers have taken big cuts in their profit margins because of the deep discounting," said Casey Willson of the Willson Co., a McLean consulting firm. "And they are hoping it will finally pay off this weekend and that consumers will respond in volume."

The discounts, most said, aren't going to get any better.

According to Irwin Zazulia, president and chief executive of Hecht Co., current discounts of 20 percent to 50 percent will stay in place over the next four days. "We're going to stick to it ... and we think sales are going to be good," he said.

"I don't think you are going to see a much bigger cut for consumers waiting until the last minute to get the right price -- people can now buy things for a song," said F. Davis Camilier, president of the 14-store Camilier & Buckley chain of specialty leather goods, which has cut prices 20 percent to 50 percent.

"It's confusing for the customer to walk into the stores with all the sales, and I think all the discounting has hardened them and made them wary of retailers," said Larry J.B. Robinson, president and chief executive of the Royal Jewelers and Antwerp Diamond Center chains, with 14 stores in Washington. "Still, prices are now low enough to attract volume but high enough to cover costs and furnish some income to us. Hopefully, this weekend will give retailers a chance to catch up after some weak sales months."

Some retailers said they were hardly discounting at all. "We have held our pricing, since most of what we offer is low in price and margins are bare bones as it is," said Kemp Mill's Applebaum.

"We have unique products and think we provide different merchandise than others," said Hodari Abdul-Ali, president of Pyramid Books, which sells African-American-oriented books at its five stores in the region.

But even without deeper price reductions, there will be intense promotion, more stock and extra employees at just about all stores. Most retailers also said they would have later hours up until early Tuesday evening.

"We are loading up our stores en masse, having more clerks and are even putting in more registers," said Cosmetic and Fragrance's Kovalsky. "We're ready for the customer."

Area malls are also planning for heavy customer traffic.

"These are likely going to be the busiest four days of the year," said Kathleen McManus, the marketing manager at Landmark Center in Alexandria. "People waited to shop, but the reality of Christmas is upon them."

At Montgomery Mall, now in the process of a massive renovation, construction has halted to accommodate shoppers.

"We want shoppers to have the easiest experience possible," said Steve Micklin, marketing director of the mall, where a 2,700-car parking deck and 15 stores opened in December.

"We've experienced a huge influx in the last couple of days," said Sherry Lewis of Springfield Mall. "We think this weekend will see a big rush."

According to retail analysts, retailers may not be far off the mark.

"Business is heating up like crazy with maximum, flat-out promotion and a lot of buying," said Howard Davidowitz, chairman of New York-based Davidowitz & Associates, a national retail consulting company.

"This could be one of the greatest weekends in retail history and prove that, even with all the economic and international trauma, Christmas is an institution that is unassailable," Davidowitz said.