The nation's largest general retailers announced their August sales results yesterday, and the numbers reflect a hard fact of life: changes in the calendar can affect consumers' buying habits and give storeowners a lackluster month.

"Generally speaking, these sales are soft," said Jeffrey Edelman, a retail industry analyst with Drexel Burnham Lambert Inc. He attributed the poor performance to delayed back-to-school shopping, although he said most stores' results were within expectations.

Retailers depend on back-to-school buying for the bulk of their August sales, but with Labor Day late this year -- falling on Sept. 7, compared with Sept. 1 last year -- many parents have put off their purchases.

"Most retailers indicated that since the end of the August sales period, sales have picked up," said Jeffrey Feiner, an analyst with Merrill Lynch & Co.

Fred Wintzer, who tracks specialty stores for Alex. Brown & Sons Inc., said smaller retailers that rely heavily on back-to-school sales had a "below trend" month, but "a lot of the back-to-school business that happened in August last year will happen in September" this year.

Some retailers echoed the analysts' assessment. Montgomery Ward & Co. said the calendar change had adversely affected its sales.

Looking at the figures, analysts disagreed about consumers' inclination to spend. "The sales are more a function of a change in the calendar rather than further weakness in the economy," Edelman said.

But, said Feiner, "Consumer spending trends remain relatively sluggish, reflecting the continued burden of high installment debt levels."

Economists keep a close eye on consumer spending, which accounts for about two-thirds of the gross national product.

The figures announced yesterday cover sales of general merchandisers and specialty apparel companies and do not include the results of such retailers as supermarkets and car dealers