Here’s a tip for all you parents who might want to allow your children to maintain their carefree, summery moods awhile longer.

Have a heart and don’t take the kids along if you have to go shopping at a department store. If they’re old enough to read, the poor things will be confronted with signs guaranteed to knock the spirit of the season right out of them as soon as they’ve passed through the front door. Summer may be only about a month old, according to the calendar, but the season is just about over in the department stores.

In our discount emporiums, in fact, it’s officially time to put aside the things of summer and start thinking about going “Back to School.”

The time bandits have struck in the night, stealing our most glorious and long-awaited season before many of us have even had the chance to take a family vacation or hit the beach for the first time. Which means, by the way, that if your daughter just lost her baseball mitt and needs another, or you accidentally backed the car over your son’s batting helmet, you can forget about finding their replacements on the shelves of your favorite department store.

“Where’s all the baseball stuff?” I asked a customer service specialist at Wal-Mart on a recent sweltering day.

“Gone, gone, all gone,” he said emphatically, jerking his thumb like an umpire signaling an out at the plate.

“But we’re at the height of summer,” I said incredulously. “Kids everywhere are playing baseball. The Red Sox aren’t even out of the playoff race yet. It’s still July.”

“Well, summer is pretty much over for us,” said the customer service specialist. “We’re gearing up for fall. Hunting, that sort of thing.”

He wasn’t exaggerating, either. I saw soccer balls, footballs, camouflaged hunting gear and other autumnal equipment. But not a single baseball, bat or glove. Unwilling to let America’s greatest summer pastime be shut down so prematurely, I went across the street to Kmart and asked directions to their baseball equipment. The clerk gave me a funny look, intimating wordlessly that I would have to be a complete newcomer to the shopping game to be so out of touch with the curious seasonal realities of the retailing world.

“We’re all out for the year,” she said with a shrug. “We pretty much stop ordering baseball equipment in March.”

After decades of shopping, I should be used to the fact that it’s becoming nearly impossible to buy an item in the season in which you intend to use it. Two summers ago, a week before leaving on an August beach vacation with the family, I went to the mall to find a bathing suit. There were sweaters and jackets and other fall apparel, and dispiriting signs everywhere announcing the opening of school, but not a single bathing suit. Frustrated and suitless, I left the mall’s fraudulent autumn behind and stepped back into the roaring hot reality outside.

One season tumbles into another these days with disorienting speed. The here and now always seems to be here and gone. The Fourth of July was less than three weeks ago and already the stores are urging the kids out of the sun and back into the classrooms. Soon we’ll be plucked out of Indian summer and catapulted straight into Halloween and the barren season of the harvest moon. By September, the advertising fliers will have us all hard on the heels of Thanksgiving and racing headlong toward Christmas.

Before you know it, the stores will be filled once again with baseball gloves and bathing suits, just in time for Easter.