We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is an Internal Clock?

Malcolm Tatum
Updated Jan 27, 2024
Our promise to you
WiseGeek is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGeek, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Also referred to as a circadian rhythm, internal clock is a term used to describe the approximately twenty-four hour cycle that is inherent in most living entities. Along with human beings, plants, other mammals, and other living creatures have an internal clock. As with a clock used to tell time, an individual’s circadian cycle is more or less constant, and is determined by both internal biological functions and external stimuli that results in behavior patterns that modify the clock to a certain extent.

The importance of the internal clock cannot be underestimated. When the clock is in sync with the day to day pattern of the individual, tasks necessary to sustain life occur on a more or less regular schedule. For example, the individual becomes sleepy around the same time each night, and is also likely to awake naturally at the same time in the morning. Cravings for food will likely occur around the same time each day. The combination of internal programming and external stimulation keep the clock functioning on a consistent basis, and thus help to ensure that the individual remains healthy.

However, external factors can also cause the internal clock to be modified. For example, people who work nights often experience a great deal of difficulty initially when it comes to getting enough rest. Assuming the individual’s internal clock is set to sleep when it is dark and rise when morning arrives, a period of adjustment is necessary before it is possible to sleep during the day. Creating a semi-dark environment in which the individual attempts to sleep can sometimes help this process of modification along. Taking this action makes it easier to establish a new sleep cycle and achieve restful slumber during the day.

Another example of internal clock modification involves travel. As an individual moves from one time zone to another, the natural rhythm may be thrown off balance. The result is what is commonly known as jet lag, a situation in which the individual feels somewhat tired and may experience insomnia until the body adjusts to the new time zone.

Evaluating the current status of the internal clock usually involves monitoring body temperature, as well as the level of melatonin produced by the pineal gland. Observing the changes in these two factors over a twenty-four hour period can make it easier to identify the current pattern associated with the body’s natural rhythm, and compare it to the individual’s daily routine. By conducting this type of research, it is possible to determine how well an individual is adapting to changes in time, place, and circumstances, and also yield clues in how to aid in that adjustment.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Malcolm Tatum
By Malcolm Tatum
Malcolm Tatum, a former teleconferencing industry professional, followed his passion for trivia, research, and writing to become a full-time freelance writer. He has contributed articles to a variety of print and online publications, including WiseGeek, and his work has also been featured in poetry collections, devotional anthologies, and newspapers. When not writing, Malcolm enjoys collecting vinyl records, following minor league baseball, and cycling.
Discussion Comments
By sputnik — On Mar 18, 2011

Since I worked night shift, or as it is also called graveyard shift, for many years, I have experienced the difficulty of adjusting to the new schedule.

I might have reset my internal clock somewhat, but never fully. I think the best way to reset the clock is by having the same schedule all the time, so even on days off it would be great to keep the same schedule as during the working week.

This is challenging though, because the rest of the family, and the rest of the world is on a different schedule, so you tend to follow theirs on your days off, and therefore never fully follow your own internal clock.

Another problem is that you really never sleep as deeply and restfully during the day, as you do during the night. Now there is some help in that area. By creating a completely dark environment in your bedroom, you have the feel of the night even though the sun outside might be at its brightest.

Malcolm Tatum
Malcolm Tatum
Malcolm Tatum, a former teleconferencing industry professional, followed his passion for trivia, research, and writing...
Learn more
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.