Kim Becker is almost finished with her back-to-school shopping, having begun it shortly after public schools let out for a shortened summer vacation last month.

Becker, the mother of a kindergartner and a second-grade student, wasn't alone. Thousands of par-ents are out shopping somewhat earlier than normal because all of Hawai'i's 182,000 public school students are now on the same schedule, with classes beginning July 27.

The shift has added a bit of uncertainty for retailers who aren't used to the new timing of the back-to-school shopping season. Local retailers generally are expecting a solid season, which is one of the bigger sales periods of the year nationally. However, sales gains aren't projected to be as big compared to the same period last year.

Becker said she is probably spending about the same amount as last year, while Niu Valley resident Amy Hamme said she may lay out a little more. In all, Hamme expects back-to-school shopping will cost her more than $300 for her three daughters.

"You can't really buy school supplies and clothes for less than $100 per kid," said Hamme, 43, who waits for sales or shops at Ross Stores, the nation's No. 2 off-price retailer.

Hawai'i's shopkeepers are having to adjust to a unified calendar, meaning almost all of the 258 state-operated schools will be on the same schedule. The change is most pronounced for about 100 schools that previously had the more traditional 10 or 11 weeks of summer calendar and began classes later in August.

"The shorter summer has affected the back-to-school shopping season," said Jasmine Tso, Ala Moana marketing and promotions director. Ala Moana, adjusting to the students' seven-week summer, has moved up its annual back-to-school teen concert to this weekend from its typical scheduling in mid-August.

She said some of the center's 260 retailers also have moved up their sales promotions, and that several said they believed sales revenue will be unchanged from last year. Summer is just seven weeks for many public school students.

"Some people are saying that because it's a shorter summer that back-to-school (shopping) has crept up on students a little sooner than they had thought," Tso said.

This weekend Ala Moana will have several promotions designed to draw teens, including different "bars" for decorating denim jeans, food and cosmetics.

At Pearlridge Center, the state's second-biggest retail marketplace behind Ala Moana, sales are still growing, though slower than last year's double-digit percentage gains, said general manager Fred Paine. He said sales should be a little more than normal for July, though Pearlridge expects back-to-school shopping will be spread over several months.

One phenomenon retailers expect to see is kids who shop for clothes after school begins so they can check out what trendsetters are wearing.

For shoppers, the solid sales projections probably mean there will be bargains to be had as retailers compete for customers, but no deep discounts that usually occur when sales are weak, Paine said.

Sales demand is "still in the plus and not the minus," he said.

Nationally, the back-to-school season may produce gains of 3 percent to 4 percent over last year, according to a projection by the New York-based International Council of Shopping Centers.

It "is likely to be OK, probably not stellar, but not a bust, either," Michael Niemira, ICSC chief economist, said in an e-mail. He is forecasting stronger book and computer sales and weaker sales for shoe and family clothing retailers.

Carol Pregill, president of Retail Merchants of Hawaii, a trade group with 200 members, said the season should turn out OK for retailers. Retailing has a correlation with employment, and Hawai'i's unemployment rate has been among the lowest in the U.S.

"What's working for us is the strong west-bound visitor arrivals and also the strong construction market," Pregill said. "People are working and have money to shop."

Reach Greg Wiles at gwiles@honoluluadvertiser.com.