Half of Americans feel they are getting a "good night's sleep" most of the time, but the other 50 percent -- including their partners -- have trouble catching enough z's, a new poll suggests.

The survey released yesterday "shows that sleep is the great American divide: half of the country sleeps well, the other half has problems," said Richard Gelula, chief executive of the National Sleep Foundation.

It released the poll to raise awareness of sleep problems and the need to treat them just before the country loses an hour of sleep with the return of daylight-saving time Sunday.

American adults say they need, on average, at least 6¹/₂ hours of sleep a night to function their best the next day, and about three-quarters of the 1,506 people surveyed said they get the minimum amount they need or more. American adults average about 6.9 hours a night. Experts still say that most people need seven to nine hours a night to feel well-rested.

But although they say they're getting enough sleep, half of those polled say they feel tired, fatigued or not up to par during waking hours at least one day a week, and only half of the respondents were able to say on most mornings that "I had a good night's sleep."

Among those who sleep with someone who has a sleep problem, 78 percent said they also frequently experience a sleep problem. And a third say they have problems in the relationship because of the partner's abnormal sleep.

Two-thirds of partnered adults say their spouse or significant other snores, while 6 of 10 of all adults say they snore. Fifty-seven percent who admitted snoring said their snoring bothers others.

When disturbed by a partner's sleep problems, the other partner loses an average of 49 minutes of sleep a night.

Thirty-one percent of those with partners who had sleep woes said they took steps to keep their own sleep from being disturbed, too, most often by sleeping in another room, another bed or on the couch.

Nearly a quarter of partnered adults say they have sex less often or have lost interest in sex because they're too sleepy.

Overall, about 25 percent of respondents said they sleep well only a few nights a month or less.