WAY, WAY BACK in the '50s, life had only two monumental questions: whether to bomb the Russians and whether to do It. Back then, doing It meant only one thing. Since The Pill, however, there seems to be no end to life's monumental questions and doing it can mean almost anything. This past winter when a college friend called to talk about doing It she was trying to decide whether to have children.

Each of us tends to praise the merits of our own choices in these crucial matters, so I found myself telling her all the good things about having children. She's now decided she is going to have at least one.

It's a good thing she didn't call me during the past week.

Something awful's been happening at home. It's not the first time this has gone on, but I'd forgotten about the previous times. When my friend called to discuss having children, I didn't tell her about childbirth.I didn't tell her about springtime, either. I drew the familiar picture of the happy American family, the one that lived in the Saturday Evening Post, when I was growing up.

But there are all sorts of secret things that go on inside American families that we never found out about in the Saturday Evening Post, things that you don't find out about until you become a mother, things even your best friends won't tell you about . . . unless you happen to call them at the right time of year.

I'm not talking about alcoholism, drug abuse, wife beating, child abuse, divorce, impotency, frigidity, and good old fights about money. We all know those things go on and there is a whole industry developing to help cure them.

What I'm talking about is still secret. It's something people talk about privately, woman to woman, man to man, over the phone or the water fountain, and it's something people only talk about with other people who have the same problem. No one else understands. It's called Children Who Wake Up in the Night. There is only one cure.

What brings this to mind is the fact that The Baby, that sainted child who slept through the night from the age of six weeks on, the very one who was so easy to care for that she was once described in this space as nearly perfect, has taken to waking up in the night. Or more precisely, she has taken to waking up in what I consider the middle of the night and others consider the top of the morning.

At first, I thought this was what isknown as a phase. It would pass in a couple of days. Then I decided she was teething. But no new teeth arrived. By the 10th day her 5 a.m. reveille calls were taking their toll. I misspelled the name of a lawyer in a column and left out the H in a judge's name. Never mind that neither of them spelled their names the way they ought to. That's no excuse. The copy editor who caught the mistakes understood. She has children. I whispered about the baby. "Of course," she whispered back sympathetically. "I've never seen you so distracted."

This is not just a working mother's problem. A Bethesda mother of three who no longer works outside the home says she is not getting any sleep this spring because her 10-month-old daughter has taken to waking up at 4:30 in the morning. "She didn't do this before," says the mother. "Our problem is that we try to get them down at 7 in the evening. We just love the free time we have and then we stay up too late and consequently don't get any rest." She finds herself getting up at 4:30, giving her baby a bottle, and trying to go back to sleep.

But her son, who is 2 years old, now gets up at 6 in the morning. She has set up a series of gates to keep him in his bedroom. "He loves to look at the Sears catalogue. So I put a tiny bowl of dry cereal on top of the Sears catalogue and he nibbles on them. He'll play for maybe a half an hour before he starts banging on the door and trying to get through all these barriers I have.

"It's exhausting," she says. "You lose your perspective on everything when you're fatigued. Depression sets in. You're grouchy." She stops and then adds darkly: "It Affects You With Your Husband."

"A lot of people take naps," she says, "but I'm not a nap person. I like things to go smoothly and I like to get things done. Plus we have responsibilities to our 9-year-old.

"They give you a break every now and then, right when you think you can't stand it any longer, and they give you a couple of extra hours' sleep. Then you think, 'My, there will be a normal life again,' and they start right back in like they were before," she says. "I use a lot of Erace makeup."

A father of two says his 23-month-old daughter has started waking up at 10 minutes to 5. "We bring her into bed with us and hope she'll go to sleep.She doesn't, of course. So my wife turns on the television for entertainment. We watch the PTL Club -- Praise The Lord."

"It's the light," says he, and he is right. Springtime has brought wonderful tulips and azaleas and dogwoods this year, but it has also brought the sunshine streaming into bedroom windows. It doesn't affect teen-agers at all. Adults can go back to sleep, unless they have little children.

For those of us who decided in our innocent pasts to do It, this is the big weekend. This is the weekend daylight saving goes into effect, and as one father put it, "I can hardly wait to lose an hour's sleep on Sunday."

Daylight Saving Time was something Benjamin Franklin came up with. Franklin fathered three children known to be his, but there is no indication he was extensively involved with them after their beginnings. He wanted to find a way to save on candles by taking more advantage of daylight and, over the decades, daylight saving time has evolved as a way to conserve fuel and power.

For those of us with little kids, daylight saving time means we may once again get a good night's sleep.