Science has repeatedly reinforced the importance of regulating mealtimes as a way of shifting the body's sleep-wake cycle. A study in 2016 found that shifting when you eat can be seriously helpful for adjusting to new time zones, particularly when you happen to have jet lag — but even if you haven't just got off a flight, the points at which you eat during a day can have big impacts on your circadian rhythm. The timing at which mice were fed during a 2017 experiment substantially affected when they slept and woke, so just trying to drop off to sleep earlier or later than usual won't do very much if you don't adjust your dinnertime accordingly.

Want to wake up earlier? Pull open the blinds and use natural light. Along with food, the human body appears to react to the rhythms of dawn and sunset to help regulate its sleep-wake cycle. Understanding how this works is still a matter of scientific research; a study in 2017 found that a kind of green algae reacts in particular to red and violet kinds of light to adjust its sleep cycle, while other research found that a substance produced by human eyes, vasopressin, appears to be one of the major ways in which the circadian rhythm is controlled, which might have something to do with light. An app called Entrain developed by university scientists might help you figure out how to adjust your light doses to your desired sleep schedule.

Sleep is the main ingredient in hacking your internal clock, and when it comes to changing it, scientists have one major piece of advice: keep it consistent. Regularity in your sleep schedule will help you adjust, regulates your metabolism (which has a role in circadian rhythms), and give you more of a chance of a decent rest. If you're changing your cycle, you have to commit to trying it every night, rather than giving up or trying to vary things gradually.

This is an unusual one, but it might prove to be more important than you think. Research published in Nature in 2017 found that, unexpectedly, one of the major ways in which the body's internal circadian rhythms is regulated within cells is through the release of potassium. It's not known yet whether or not adjusting your levels of potassium consumption could have any tangible effect on how you sleep and wake, but it's worth keeping up your intake of bananas, sweet potatoes, and spinach just in case.

Trying to adjust your circadian rhythms is tough at the best of the times, but research in early 2017 indicates that it's substantially tougher if your roommate or sleep partner isn't going along for the ride. If your girlfriend happens to be predisposed genetically towards being a night owl, she's likely going to be keeping you up; commitment to shifting towards other types of circadian rhythms requires everybody in the vicinity to try it at once. But if she finds it tougher than you (again, genetics), don't be surprised.

Researchers at Stanford in 2015 investigated a fascinating new possibility for shifting biological rhythms: sharp, shorp pulses of light. Apparently, being subjected to an hour of 2-millisecond flashes of light every 30 seconds while in deep sleep won't wake you up, but it will make you wake up an hour earlier in the morning. At the moment, this light pulse therapy isn't available in easy mechanisms on the market, but it's worth keeping an eye open in case it happens to be an option soon.

The Withings Aura alarm clock is one of a range of alarm clocks on the market that attempt to use types of light to shift circadian rhythms in sleepers. It's a sleep-tracker that also uses colored LEDs — blue in the morning, red and orange in the evening — to simulate the kinds of light that occur naturally in the environment and induce sleeping and waking. The Lumie alarm clock does the same but without color, and it's worth testing whether they shift your sleep cycle to help your hacking.