Here’s some shocking news: There are 40 more days until the kids go back to school.

If that sounds like a long time to you, break it down. Ten sets of four days. Four sets of 10 days. Anything to make it seem like fewer days in the desert of summer parenting. Anything that heralds the possibility of more sleep and just a little less late-night family life.

You think I’m a spoilsport? Fine. But I’m not having much fun this summer. Oh, the kids are, all right. Summer is like a perpetual weekend for them. They’re going to the movies, bowling, cavorting, cruising in the car and, with teen-agers, who knows what else. The big point is they stay up late. Way late. Every night.

And my job is to keep up with them, know where they are, what they are doing.

Ha, ha. Ha, ha, ha.

The upshot is that I’ve been staying up unbearably late on weeknights, which for me are also work nights. With sleepy eyes, I sit on the couch and try to read until 15 minutes before the kids have to be home. That’s just enough time for me to pull myself upstairs and change into my pajamas. When the clock chimes that be-home-or-else hour, I slip into bed and wait to hear the front door slam. (Does a teen-ager ever just close a door?)

Often by that time, I am irreversibly wide-eyed. Stuck in a state of useless alertness, I try to read, but it’s more common for me to slink down the stairs and doze during one of the hundreds of films we’re destined to rent this summer. An hour later, I get a stern wake-up call: “Go to bed.”

Usually, I’d say it’s a routine that’s workable only for about 12 weeks.

But then on a recent Tuesday night, I got a call a half-hour before midnight. It went something like this:

“Mom, I’m at the bowling alley and I can’t find a ride home ’til midnight. You go ahead and go to bed. I’ll lock up when I get in.”

Now that’s the kind of curve ball a teen-ager should intuit as a bad move late on a Tuesday night with an exhausted parent.

“You’re grounded,” was my response. “See you at midnight.”

For the first time in her 16 years, my kid was grounded. She had to be home several hours early the next night and lost the use of my car for a week. It felt awkward to each of us when I doled out the terms. I mean, it’s a little late in the game to be handing out punishments. But my move had a symbolic rather than punitive motive: Don’t mess with my sleep habits.

“I hope it was worth it,” I said to her in my best parental voice.

“It was,” she assured me. “You don’t ever let me use the car anyway.”

The next night, I looked forward to going to bed early. At the appointed hour, my daughter arrived home with a stack of videos.

“I’m so excited that I’m grounded,” she said giddily. “I’ve never been grounded before. I’m going to watch all these movies.”

It was not the attitude I had hoped to inspire. I had to admit, however, she got some great movies, which we sat up late watching.

So much for a good night’s sleep.

Forty days and counting.