NEW YORK (AP) — The holiday shopping season turned out to be two seasons split by a big lull.

A surge in buying in the two weeks before Christmas coupled with a record-breaking Black Friday gave retailers a solid season. The doldrums between the buying binges show how shoppers have learned to wait for the discounts they know will come.

For Dec. 1-24, spending rose 4.7 percent compared with the same period last year, according to research firm ShopperTrak. In November, it rose 4.1 percent. A 4 percent increase is considered a successful season. A combined figure for the whole season won't be available until after Dec. 31.

The increase is good news for the economy, because it shows shoppers were willing and able to fund a holiday splurge. Consumer spending, including major items such as health care, accounts for 70 percent of the economy.

Still, plenty of shoppers are pinched for cash in the slow economic recovery, and were seeking the best deals. Stores have trained even shoppers who are primed to spend to look for a discount.

In the week before Christmas, last-minute shoppers gave retailers a 4.5 percent increase in revenue at stores open at least a year with the same week last year, according to the International Council of Shopping Centers-Goldman Sachs Weekly Chain Store Sales Index.

The index estimates sales at 24 major stores including Macy's Inc. and Costco Wholesale Corp. Revenue at stores open at least a year is an important measurement of a retailer's performance because it excludes the effects of stores that open or close during the year.

Total retail revenue for the week ended Saturday rose 14.8 percent compared with the year ago, ShopperTrak estimates.

Gift buyers gained steam as the season went on. The store revenue figure rose 0.9 percent last week from the week before, building on a 3.4 percent increase the week before that.

"The downs and ups were much more accentuated," said Michael P. Niemira, chief economist at the trade group. "It just shows how cautious the consumer is. Consumers are bargain hunters more today than ever before."

The post-Black Friday lull was deeper than usual this year. The two weeks after Thanksgiving weekend showed the biggest percentage sales decline since 2000. Then, during the final two weeks before Christmas, sales surged again, by the highest rate since 2005, Niemira said.

"The holiday season was good but uneven," Niemira said.

Stores are expected to benefit when shoppers come back to spend their gift cards, because people often spend more than the cards' value. In addition, gift card sales are recorded only when shoppers redeem them.

People have more money on their cards to spend. According to an ICSC-Goldman Sachs survey of shoppers conducted Sunday, 18 percent of holiday spending went toward gift cards, up from 14.6 percent last year.

ICSC said it expects holiday sales for November and December to rise in line with its forecast of 3.5 percent.

The week after Christmas, which includes six shopping days, should be strong. But it's being compared with seven days last year because the week as retailers measure it ends on Saturday.

As proof that consumers are timing their spending to when they know they'll get the best bargains, Black Friday, the day after Thanksgiving, was the biggest sales day, as expected, generating sales of $11.4 billion, up 6.6 percent from a year ago, according to ShopperTrak.

But based on preliminary data, Christmas Eve and Dec. 26 were the second- and third-heaviest spending days of the season, according to ShopperTrak founder Bill Martin. He had originally expected Saturday, Dec. 17, to be the second-largest. Christmas Eve wasn't even forecast to be among the top 10 days.

"Shoppers are willing to spend when they know the biggest discounts are available," said Martin.

ShopperTrak measures foot traffic in 25,000 stores in the U.S. and blends those figures with economic data along with proprietary sales figures from merchants. The data excludes sales from auto dealers, gas stations, restaurants and grocery stores.

A fuller holiday spending picture will come Jan. 5, when stores including Target Corp. and Macy's will release December sales figures.