Flickr/Flying Kiwi Tours
  • In a new study, researchers pinned down five factors that appear to be strongly linked with a significantly longer life.
  • All five of the factors are related to lifestyle and include things like diet and exercise.
  • Women in the study with the strongest adherence to all five factors lived an average of 14 years longer than their female peers who adopted none of them; men lived an average of 12.2 years longer.

The road to a long life is littered with hype. There are the usual suspects, like pricey pills and supplements, as well as the peculiar, such as infusions of blood from young mice or standing-room chambers pumped with sub-zero temperatures.

And then there’s science.

As is frequently the case, the real ways to improve your health happen to be mundane. Thankfully, however, that also means you wield a significant amount of power over these factors.

In a new study published in the journal Circulation, researchers at the American Heart Association pinpointed five lifestyle factors that appear to be linked with a significantly longer lifespan, judging by the outcomes of two long-term studies that involved roughly 123,000 adults.

All of the factors are things that can largely be changed, like quitting smoking or eating healthier. In the studies, women who adopted all five of the factors enjoyed roughly 14 extra years of life on average compared with their peers who adopted none of them; men got an average of an extra 12.2 years.

Keep in mind that these are averages. These conclusions do not mean that suddenly putting all five factors into practice will lengthen your life by a decade. All we can say definitively, judging by this research, is that people with these traits tend to live longer than people with few or none of them. With that in mind, here are the five factors:

At least 30 minutes of daily cardio exercise

woman running jogging exercise


Cardio exercise is an all-natural way to lift your mood, improve your memory, and protect your brain against age-related cognitive decline. In other words, it’s the closest thing to a miracle drug that we have.

A wealth of recent research suggests that cardio – any type of exercise that raises your heart rate and gets you moving and sweating for a sustained period of time – has a significant and beneficial impact on the brain.

“Aerobic exercise is the key for your head, just as it is for your heart,” said a recent article in the Harvard Medical School blog “Mind and Mood.”

Most research suggests that the best type of aerobic exercise for your mind is anything you can do regularly and consistently for 30 to 45 minutes at a time, bringing it in line with the latest study findings.

Eating like a Mediterranean

salmon asparagus vegetables fish healthy meal dinner plate


It often seems like there can’t be a single best diet for your health.

But a growing body of research suggests that a meal plan focusing on vegetables, protein, and healthy fats has key benefits for losing weight, keeping the mind sharp, and protecting the heart and brain as you age. The new study bolsters that research, finding that eating this way is also linked with living longer.

Like drinking, dietary habits were self-reported, but the study’s general findings are supported by dozens of previous studies. Researchers looked at aspects of previously agreed-upon standards for healthy eating, including high intakes of vegetables, fruit, nuts, whole grains; healthy fats like those from fish and olive oil; and low intakes of red and processed meats, sugary beverages like soda and juice, and trans fats and salt.

Never smoking


Matt Cardy/Getty Images

Smoking kills. No other habit has been so strongly tied to death. In addition to cancer, smoking causes heart disease, stroke, lung diseases, diabetes, and chronic obstructive pulmonary disease, which includes emphysema and chronic bronchitis, according to the Centers for Disease Control.

Smokers inhale burned tobacco and tar along with toxic metals like cadmium and beryllium, and elements like nickel and chromium – all of which accumulate naturally in the leaves of the tobacco plant.

So it’s no surprise that the latest study found evidence that abstaining from cigarette smoking for life was linked with living longer. But if you’ve already smoked, the research still has good news: both quitting and cutting back were also linked with positive outcomes related to life expectancy.

“Smoking is a strong independent risk factor of cancer, diabetes mellitus, CVDs, and mortality,” the researchers wrote, “and smoking cessation has been associated with a reduction of these excess risks.”

Sticking to a healthy body weight

weight loss body scale


When it comes to quickly assessing the health of large groups of people, a measure called body mass index, or BMI, can be helpful. Generally speaking, a BMI of between 18.5 and 24.9 is considered within the “healthy range” for healthy adults over age 20, according to the CDC.

Because of this, it makes sense that the latest study used this BMI range to define what they considered an “optimal” body weight. Essentially, they found that people who fell within that BMI range tended to out-live people who fell outside of it and were either over- or under-weight.

From an individual perspective, however, BMI is far from a perfect means of gauging your overall health. The 1830s-era measure does not take into account a number of key health factors, including overall body fat, gender, muscle composition, or the amount of fat you’re carrying around your middle, also known as abdominal fat. Abdominal fat, (as measured by your waist circumference) is emerging as a key alternative to BMI because of its strong links with heart health and diabetes. Plus, it’s really easy to do.

Drinking no more than 1 to 2 alcoholic beverages a day

red wine pouring glass


Several studies attempting to pin down the precise relationship between drinking and overall health have come up short, with often conflicting results.

These studies can be problematic because they include small research samples or rely on people to accurately self-report their drinking habits. Another big problem is that what most of us consider “moderate” drinking is really far from it: according to the National Institutes of Health, moderate drinking is one drink per day for a woman and two drinks per day for a man. Up to a third of Americans regularly exceed these levels.

That said, some previous research has linked such “moderate” drinking with beneficial outcomes, including a lower risk of certain diseases like diabetes.

The new study again relied on people’s self-reported alcohol habits, so they need to be taken with a grain of salt. Still, the researchers concluded that one drink per day for women or two drinks per day for men was linked, on average, with a longer life.

  • The US is getting healthier overall, but in 21 states death rates increased for people aged 20 to 55 from 1990 to 2016.
  • That’s according to the latest results from the Global Burden of Disease Study, which has tracked health outcomes in the US and around the world since 1990.
  • The increase in deaths for young and middle aged people is being driven by drug and alcohol use, suicide, and kidney disease, among other related factors.

The opioid crisis, alcohol use, suicide, and factors like chronic kidney disease are increasing the likelihood that some Americans will die an early death.

In 21 US states, the chances that someone will die between ages 20 and 55 actually increased between 1990 and 2016, according to a study newly published in the Journal of the American Medical Association. This data comes from the ongoing Global Burden of Disease Study, which has tracked health outcomes in the US and around the world since 1990.

Over that time in five states – Kentucky, Oklahoma, New Mexico, West Virginia, and Wyoming – the chances people aged 20 to 55 would die increased by 10% or more.

In the US in general, there’s a pretty extreme disparity of health outcomes that can be observed based on where a person in born. People born in certain states are much more likely to die an early death and to live fewer healthy years when compared to people born in healthier states.

At birth, a child born in Mississippi in 2016 had a life expectancy of 74.7 years. That’s 6.6 fewer years than a child born that same year in Hawaii, who could be expected to live to 81.3, according to the study.

On a county level, these distinctions are even more stark. A study published last year found a more than 20-year difference in life expectancy when comparing kids born in Summit County, Colorado (2014 life expectancy of 86.83) to those born in Oglala Lakota County, South Dakota (2014 life expectancy approximately 66.7).

But the increasing rates of death at a young age in 21 states are particularly concerning, as they are largely due to preventable factors like drug or alcohol use, suicide, or kidney disease (which may be related to drug or alcohol use).

The following chart shows the US states, with those where people are most likely to die between ages 20 and 50 at the top. For each state, you can see how much the chances people would die early have dropped on the left side of the dotted line. On the right side of the dotted line, you can see how much the chances people could die early have increased. In each case, color coding shows what’s behind the increases and decreases.

Change in the probability of death between ages 20 and 55 years, 1990-2016. States are listed in descending order according to probability of death in 2016.

Change in the probability of death between ages 20 and 55 years, 1990-2016. States are listed in descending order according to probability of death in 2016.
US Burden of Disease Collaborators, JAMA, 2018

In some states, there has been a significant improvement in the death rate for young and middle-aged people, with the biggest improvements seen in New York and California. In total, 15 states saw improvements by 10% or more, mostly due to declining death rates from HIV/AIDS, road injuries, and related to tumors.

In general, the largest risk factors for death in the US are poor diet, tobacco use, high blood pressure, obesity, and high blood sugar.

As the researchers wrote in the study, the US overall is healthier than in 1990. But the country spends more on healthcare than any other country and still ranks 43rd in global life expectancy. And even as there have been improvements, there are also factors that are causing some states to fall further behind.

As physicians Dr. Howard Koh and Dr. Anand Parekh wrote in an editorial published in JAMA along with the new study, “[m]uch unfinished business faces the nation collectively and at the state level.”

Sarah Jacobs/Business Insider
  • A growing body of evidence suggests regular meditation is linked with benefits including lower stress and better focus – a key trait that dissipates with age.
  • Meditation is also one of Silicon Valley’s hottest trends, with everyone from startup employees to CEOs adopting the practice.
  • And a new study suggests that the benefits of meditation could be more long-lasting than we thought, depending on how much time you can devote to the practice.

Stop. Breathe. Let everything go.

Giving your mind a break from bustling thoughts may empower it to run more efficiently.

The merits of meditation haven’t gone unnoticed amongst engineers and CEOs in Silicon Valley. Salesforce CEO Marc Benioff, Twitter CEO Jack Dorsey, and Google co-founder Sergey Brin are all well-known meditators, and their companies provide opportunities for employees to do so as well. At a recent health and technology conference organized by Forbes in Southern California, the day began with a 45-minute beachside group meditation hosted by author Agapi Stassinopoulos; later on, Andy Puddicombe, the co-founder of the $250-million dollar mindfulness app Headspace made an appearance to guide participants through a mini meditation session.

A growing body of research on meditation suggests that even a few minutes of daily mindfulness is linked to lower stress levels, more positivity, enhanced creativity, and even better focus. That last trait, the ability to focus, is something that can begin to falter with age, but a new study suggests that meditating could be one way to help prevent this decline.

For a study published this week in the Journal of Cognitive Enhancement, researchers concluded that people who participated in a meditation retreat and continued to meditate daily had a superior ability to pay attention compared with those who either didn’t attend the retreat or failed to maintain a regular mindfulness practice.

Although enhanced focus has previously been identified as one potential benefit of meditation, this is the first study of its kind to suggest that those benefits can last as long as up to seven years, or the length of the study.

“This study is the first to offer evidence that intensive and continued meditation practice is associated with enduring improvements in sustained attention,” Anthony Zanesco, the lead author on the new paper and a postdoctoral researcher at the University of Miami who began work on the analyses before starting his PhD program in psychology at the University of California, Davis, said in an emailed statement.

While previous research has suggested that meditation is a powerful tool to clear the mind, the most recent study suggests that it may also be a potent means of protecting it from some of the negative effects of aging, such as a reduced ability to pay attention.

Mindfulness is a powerful tool to clear and protect the mind

working resting break meditating thinking coffee

Jacob Lund/

Something about meditating – whether it’s the physical space we set up for ourselves each day or the mental space we make by regularly clearing the mind – seems to help us deal with the worrisome thoughts that can come up in our day-to-day lives.

It’s somewhat like taking a broom to the bustling thoughts that can crowd our heads and then waiting until all the dust has settled.

Several studies have found links between this mind-clearing and an immediate, measurable reduction in feelings of depression and anxiety as well as physical pain.

But the most recent study suggests that those benefits can be made to last a lot longer than a few minutes or hours – depending on how much time and space you can dedicate to your mindfulness practice.

For the research, 60 adults aged 22 to 69 with an extensive background in meditation were randomly assigned to either attend a three-month meditation retreat in Colorado or to be wait-listed for the retreat while still traveling to the retreat location for week-long assessment periods.

Those who attended the retreat were immersed in a hefty program of intense meditation. Not only did they learn meditation techniques from B. Alan Wallace, a Buddhist scholar and author from the Santa Barbara Institute for Consciousness Studies, they also meditated in groups twice a day and did their own mindfulness practice, totaling to about six hours of mindfulness each day.

At the end of the retreat, the researchers tested the participants on standard measures designed to assess their ability to maintain attention, their overall psychological well-being, and their ability to handle stressful situations. Those who participated in the meditation retreat and maintained a daily, roughly one-hour meditation practice fared significantly better than those who did not – a finding that held true both at six months, 18 months, and even at seven years.

Meditating may boost our ability to focus and empathize

meditating relaxing yoga exercise

Strelka Institute/Flickr

When we go into a quiet room and block out a period of time for our minds to go blank, it appears to make it easier for us to enter a state of intense focus later on.

Richard Davidson, a neuroscientist at the University of Wisconsin, looked into this idea for a long-term study published in the journal Emotion in 2012. For his analysis, Davidson compared people who had been meditating for years with complete beginners.

He found that when he tried to startle two groups of people – one that was meditating and one that was not – with a sudden interruption like a loud noise, the meditators were far less perturbed by the interruption than the people who weren’t meditating, regardless of whether they were new or experienced at the practice.

In a follow-up analysis, Davidson played the sounds of stressed-out voices to groups of experienced meditators and beginners, and then observed their brain activity patterns in an MRI. While he noted increased activity in two brain areas known to be involved in empathy among members of both groups, the activity was significantly more pronounced in the brains of the experienced meditators. People who meditate regularly, Davidson concluded from this work, might have an enhanced ability to respond to others’ feelings and empathize with them without feeling overwhelmed.

All of these potential benefits may have had an effect on the participants in the most recent study. Instead of disturbing participants with noises, the researchers involved in this paper had them discriminate between visual targets on a set of tests, and found that meditation appeared to significantly improve their performance.

“The present study suggests that intensive and continued meditation is associated with enduring improvements in sustained attention, supporting the notion that the cognitive benefits of dedicated mental training may persist over the long-term when promoted by a regimen of continued practice,” the researchers wrote in their paper.

Many people say they experience an energy boost while doing intermittent fasting.

Many people say they experience an energy boost while doing intermittent fasting.
Jacob Lund/Shutterstock

It’s odd to think that depriving yourself of a necessity for life might be one of the most powerful ways to transform your health.

Yet there’s more and more evidence for the idea that fasting could have powerful health benefits for both the body and brain.

There are many different forms of fasting, however, ranging from going extended periods of time without food to consistently eating less (perhaps cutting caloric intake by 20%) to intermittent or periodic fasting.

But of all these different kinds of fasting, intermittent fasting is very likely the most popular and certainly the trendiest one. Celebrity adherents include Hugh Jackman, Tim Ferriss, and Beyonce. In Silicon Valley, whole groups of self-optimization obsessed biohackers meet to collectively break their fast once a week, and executives at companies like Facebook say that fasting has helped them lose weight and have more energy.

The hard part about classifying “intermittent fasting” is that there are a number of different forms of this kind of fast. Intermittent fasting regimens range from only allowing yourself to consume calories within a certain span of the day, likely between six and 12 hours; to eating normally five days a week and dramatically cutting calories on two fasting days; to taking a 36-hour break from food every week.

The different forms these fasts can take mean that much of the research showing benefits might be true for one of these fasts but not necessarily others. But there is good research on several of these fasts indicating that the benefits of intermittent fasting go beyond weight loss. There may be real long-term disease-fighting health improvements.

Here’s what we know so far.

A recent study suggests that intermittent fasting can do more than help people lose weight — it also may improve blood pressure and help the body process fat.


For this small study, researchers had overweight participants either cut calories every day or eat normally five days a week and only consume 600 calories on their two fasting days.

Both groups were able to lose weight successfully, though those on what’s known as the 5:2 diet did so slightly faster (though it’s not clear the diet would always help people lose weight faster).

More significantly, those from the intermittent fasting group cleared fat from their system more quickly after a meal and experienced a 9% drop in systolic blood pressure (the “regular diet” group had a slight increase in blood pressure).

This was a small study and researchers say participants had a hard time following the diet, but these are promising results.

Other studies indicate intermittent fasting could reduce risk for forms of cancer, but more research is needed.

Dan Kitwood / Getty Images

Other small studies on a similar 5:2 diet and on other intermittent fasting diets have shown that this form of intermittent fasting is associated with physical changes that could lead to reduced cancer risk, particularly for breast cancer.

Much more research on this area is needed, but these are promising results, Mark Mattson, a neuroscientist at the National Institute on Aging at the National Institutes of Health, previously told Business Insider.

There may be evolutionary reasons why depriving ourselves of food for some time makes us feel energetic and focused.

Neanderthal paintings can be seen in a cave in Pasiega
Thomson Reuters

“Hungry,” from an evolutionary perspective, isn’t lifeless or drained. It’s when our bodies and brains need to function at maximum capacity.

“It makes sense that the brain needs to be functioning very well when an individual is in a fasted state because it’s in that state that they have to figure out how to find food,” Mattson previously told Business Insider. “They also have to be able to expend a lot of energy. Individuals whose brains were not functioning well while fasting would not be able to compete and thrive.”

Periodic fasting may make it easier for us to burn fat and enter ketosis.


Blood samples have shown that people who fast from 12 to 24 hours at a time enter a state called ketosis, when their bodies start to derive more energy from fat, Mattson told Business Insider in another interview.

The more you enter this state, the better your body gets at using fat as fuel. For that reason, some people try to trigger ketosis with “keto” diets that involve consuming a lot of fat. But according to Mattson, fasting is a significantly more effective way of boosting ketone levels.

Intermittent fasting may strengthen neural connections and improve memory and mood.

human brain connectome
Human Connectome Project, Science, March 2012.

Many people who fast intermittently say that at times, they feel more clear and focused while fasting.

There’s real science to back up the idea that being “hungry” gives you a sense of focus. Entering ketosis triggers the release of a molecule called BDNF, which strengthens neurons and brain connections linked to learning and memory.

That’s one of the reasons researchers have suggested that ketogenic diets (both the fasting kind and the fat-heavy kind) could be useful for people fighting degenerative brain diseases like Alzheimer’s. That also could explain the clarity or focus some people feel after fasting. It may provide a mood boost as well.

Research indicates that some forms of intermittent fasting may help with diabetes.


Both in mice and in people, there’s evidence that certain forms of intermittent fasting can improve the body’s response to sugar. In mice, researchers have basically been able to reboot the pancreas, which produces insulin, reversing diabetes with periods of fasting like the 5:2 diet.

In people, a form of fasting that involves 25 days of unrestricted eating followed by 5 days of eating a very restricted fasting diet seems to cause big improvements for those with high blood sugar.

Intermittent fasting works at least as well as other forms of dieting for weight loss.

Shutterstock/Siberian Photographer

No form of restricting food is necessarily easy, and people who get started with intermittent fasting for the first time agree that it’s no picnic. On the one hand, it’s nice to eat whatever your want when your diet isn’t restricted – but it’s also very hard to know you are still hours away from food when struck with a craving.

But research does indicate that intermittent fasting is at least as good as other forms of dieting for weight loss. That plus the other health benefits might make it a preferred candidate for many.

Certain forms of fasting are associated with anti-aging health effects, though it’s not clear whether intermittent fasting does this for humans.


Various forms of fasting have been associated with significantly improved lifespan and healthspan – the time an organism is healthy – in several different studies.

This has mostly been demonstrated with caloric restriction in animals, which cuts the amount of calories these animals are provided by 20-30%. There’s limited evidence that this may work for humans too.

But that sort of fast doesn’t sound necessarily safe or pleasant.

Valter Longo, an anti-aging researcher at the University of Southern California, has published research and written a book about a diet he’s developed that he says provides the health and anti-aging benefits of fasting while still letting people eat normally 25 days a month (the other five are pretty rough).

It’s unclear whether intermittent fasting would trigger the same benefits, though it’s possible.

More research is still needed on the different forms of intermittent fasting.

Kevin Lamarque/Reuters

It’s appealing to think that fasting might be an ancient survival mechanism that triggers healing processes in the body, as many fasting researchers suggest.

But that doesn’t mean all forms of fasting are the same or that they have the same health effects – many will vary from person to person, and you should always consult your doctor before trying any severe dietary changes.

In his new book, “The Longevity Diet,” Longo cautions against using the term “intermittent fasting” too broadly. We know various forms of fasts – only eating during certain hours, restricting eating one or two days a week – are associated with health benefits. But we don’t know that all these health benefits are the same for all fasts.

But even so, many of these intermittent fasting regimens are considered relatively safe for a healthy person. So if they appeal, they could be worth a shot. And they may come with a host of health benefits.

  • A growing body of evidence finds that cardio exercise is the closest thing to a miracle drug that we have.
  • Cardio, otherwise known as aerobic exercise, has been tied to benefits ranging from better moods and a stronger heart to a sharper mind.
  • To get the most out of your swimming, running, or walking routine, studies suggest you should commit to doing it at least 2-4 times per week. Each workout should be at least 30-45 minutes.

Want an all-natural way to lift your mood, improve your memory, and protect your brain against age-related cognitive decline?

Get moving.

A wealth of recent research, including a new study published this month in the Journal of Alzheimer’s Disease, suggests that any type of exercise that raises your heart rate and gets you moving and sweating for a sustained period of time – known as aerobic exercise – has a significant, overwhelmingly beneficial impact on the brain. Those benefits may start to emerge as soon as you start working out regularly.

“Aerobic exercise is the key for your head, just as it is for your heart,” write the authors of an article in the Harvard Medical School blog “Mind and Mood.”

woman running stretching fitness exercise jogging


For the latest study, researchers at University of Texas Southwestern Medical Center looked at a sample of older people who showed early signs of memory loss and were at risk of developing Alzheimer’s. The less frequently the participants exercised, the weaker the connections in their brain’s white matter and the more poorly they performed on a bunch of cognitive tests.

“This research supports the hypothesis that improving people’s fitness may improve their brain health and slow down the aging process,” Kan Ding, a neurologist with the Peter O’Donnell Jr. Brain Institute and the lead author on the paper, said in a statement.

Exercise may help keep the brain young

As we age, the brain – like any other organ – begins to work less efficiently, so normal signs of decline begin to surface. Our memory might not be quite as sharp as it once was, for example.

Exercising regularly as we get older appears to help defend against some of this decline, both for healthy people who show normal signs of aging and for older people who may be on the path toward developing Alzheimer’s disease.

Researchers still aren’t sure why this is, or how it happens. Exercise could strengthen some of the pathways our brain uses to relay signals for recent events, or boost the size of certain brain regions that are key for learning and storing memories.

older man elderly man jogging nature running exercise thinking outdoors


Regardless of the specific mechanism at play in our bodies, the most recent recommendations suggest that working out twice a week may be beneficial in curbing some symptoms of mild cognitive impairment (MCI), a stage that precedes the development of Alzheimer’s in some older people. This typically involves more serious problems with memory, language, thinking, and judgment than those that might be displayed by a healthy older person.

Most studies focusing on people with MCI require people to either work out or self-report their own fitness levels. But the latest study measured how fit people were by studying their breathing and heart rate. The researchers then used brain imaging to measure the functionality of peoples’ white matter and had them take a series of cognitive tests designed to measure how sharp they were.

Overall, they found that the less fit people were, the weaker their brain’s white matter connections, and the worse they did on the cognitive tests.

Two other recent studies of older people with MCI have suggested that merely amping up one’s workout routine with the right moves could help slow the brain’s decay.

Last May, scientists recruited adults with MCI between the ages of 60-88 and had them walk for 30 minutes four days a week for 12 weeks. The results showed strengthened connectivity in a region of the brain where weakened connections have been linked with memory loss. That development, the researchers noted, “may possibly increase cognitive reserve,” but more studies are needed.

Another study, this time of exclusively older women with MCI, found that aerobic exercise was tied to an increase in the size of the hippocampus, a brain area involved in learning and memory.

Large groups of researchers are taking note of these promising findings. In December, the American Academy of Neurology updated its guidelines to reflect the takeaways of these findings. Based on a series of 6-month studies on aerobic workouts and memory in people with MCI, the new guidelines recommend that people diagnosed with the condition do some form of cardio exercise at least twice a week.

Working out could boost your mood, too

In addition to protecting the brain from aging, cardio workouts “have a unique capacity to exhilarate and relax, to provide stimulation and calm, to counter depression and dissipate stress,” according to the article in Harvard’s “Mind and Mood” blog.

The reason aerobic workouts lift our spirits seems related to their ability to reduce levels of natural stress hormones, such as adrenaline and cortisol, according to a study in the Journal of Physical Therapy Science. Activities like running and swimming also increase overall blood flow and provide our minds fresh energy and oxygen – another factor that could help us feel better.


Flickr / Dave Rosenblum

Aerobic exercise may also have a uniquely powerful positive impact on people with depression. A pilot study in people with severe depression found that just 30 minutes of treadmill walking for 10 consecutive days was “sufficient to produce a clinically relevant and statistically significant reduction in depression.”

So whether you’re looking for benefits related to mood or memory, the take-home message is clear: the more you move, the healthier you may be.

“It’s exciting that exercise may help improve memory at this stage, as it’s something most people can do and of course it has overall health benefits,” Ronald C. Petersen a fellow of the American Academy of Neurology and the lead author on the most recent guidelines, said in a statement.

While some benefits of exercise can emerge just a few minutes into a sweaty workout, others might take several weeks to crop up. That means that the best type of fitness is any aerobic exercise that you can do regularly and consistently for at least 45 minutes at a time.