Hacking Your Biological Clock: My 21-Day Experiment with Sleep and Light

Elijah Szasz
6 min readAug 25, 2023


Accessing the Wonder Drug

For the longest time, I viewed sleep as downtime — not good. It was more like an unavoidable chunk of my life that robbed me of getting more things done. I tried everything I could to work around it, from crashing only a few hours a night to experimenting with polyphasic sleeping. I’ve come to cherish the sanctity of good sleep. When viewed through the lens of a life quality enhancer, nothing else can do more to boost your mood, immune system, and creativity. But these great benefits don’t come from restlessly tossing, turning, or staring at the ceiling for hours on end. After years of trying to cheat the sleep game, I likely did some damage to its natural systems. While there are dozens of things that can derail a good night’s sleep, I decided to spend three weeks trying to fix the most fundamental one.

The World’s First Clock

Like most of my obsessions, this one for sounder sleep led me to my primal roots and contentious relationship with technology. In the days long before electric lamps, life revolved around the sun's rising and setting. Therein lies the foundation of circadian cycles, the 24-hour rhythms that can be observed in all people, plants, and animals. This can be traced back to some of the earliest cells with photosensitive proteins. Protecting the DNA from the ultraviolet radiation during the day, the cell’s replication would only occur at night. Humans have been trying to extend daylight since about 70,000 BC. A hollow shell or rock filled with moss or sponge soaked with animal fat would burn for a little while past sunset. This tech evolved into lamps with a more robust body, wicks, and longer-lasting fuel sources. By the end of the 18th century, lamps were ubiquitous among most human cultures. Even so, they were a far cry from today’s high-pressure sodium discharge lamps. So when the sun went down, the day was over. Work was done, battles were put on hold, and people slept.

My, How Things Have Changed

Let’s stop and think about the hundreds of thousands of years humans have spent with life exclusively revolving around the sun. If we throw in the evolution of photosensitive proteins, we can even call it hundreds of millions of years. As a species, our time spent around light after sunset has been negligible on an evolutionary scale. The countless systems in our body that depend on these rhythms include regulating body temperature, cortisol, blood pressure, melatonin, growth hormone, testosterone, and metabolism. Fast forward to the Industrial Age and work days that transcend far past nightfall or even began at dark. Enter the recent Digital Age and the widespread nighttime use of color television and computer screens. If you think this behavior might squarely oppose the essence of how we’re wired, you’re absolutely correct.

Light and Your Biological Clock

Our “master clock” is in the suprachiasmatic nuclei (SCN) in the brain's hypothalamus. The SCN regulates hormone production, metabolism, and sleep by taking external cues such as light and darkness. Researchers have recently found evidence of a system in the eye entirely independent of the light-detecting proteins found in the rods and cones. A protein named melanopsin, particularly sensitive to blue light, is now believed responsible for carrying the signals to the brain’s master clock. These blue lights, prevalent in the screens we surround ourselves with, tell your brain to wake up and set off a cascade of other biological actions. It’s no coincidence that the increased use of screens in our homes tracks the rise in sleeping disorders.

The Circadian Challenge

For 21 days, I decided not to use any electrical lights, computer screens, or TV after sunset. My family was also subject to this experiment, although my daughter would go into her room and close the door, not into the idea of doing her homework by candlelight. The light emitted from fire does not include blue light in its spectrum as the white incandescent, fluorescent, and halogen sources. If I had to leave the house after sundown, I wore glasses with orange lenses to keep as much blue light as possible from hitting my eye’s melanopsin proteins. We stocked up on candles and a handful of kerosene lanterns. As it turns out, life before electricity had many health risks and even today, not all candles and lantern fuels are created equally. After a bit of research, we found organic, clean-burning options. LED fake candles are also the most sustainable and create a lovely light. But like the orange glasses, those felt like a bit of a cheat for this primal experiment.

Cooking by candlelight


  • After a few evenings spent in candlelight, something very noticeable happened. Several hours before we’d usually turn in for the night, my wife and I felt hit by tranquilizer darts. It was beyond feeling relaxed. It was more like an innate pull to sleep, so we did that.
  • Historically, rising with the sun meant I wasn’t getting as much sleep as usual. When you go to sleep that early, waking up at sunrise isn’t a huge deal. Early mornings are beautiful. The stillness and absence of the usual morning rush are lovely. I also shifted some morning routines so I could get to work earlier, get way more done before the phone and Slack started, and then get home early.
  • Cooking in the dark is challenging. Half of our experiment went down before the daylight savings switch, so it was dark by 5pm. If you throw enough fire in a given area, it can get pretty well-lit, but it still isn’t the same as a bright overhead electric light. After the time switch, getting ready for nightfall, especially cooking, was much more relaxed.
  • There was a charming ritualistic piece to the whole thing. I had to leave work early and remove all the lamps and candles before sunset. The family would sit down for dinner with the candles, and there was a sense of serenity, unlike the usual glare of electric light.
  • Before electricity, people who read at night were called wax drippers. Now I know why. After a few nights of eye strain, I decided that the backlit e-ink Kindle display used with the orange lensed glasses was just generally better for my eyes and felt much more relaxing. I was already so tired from the candlelight that I was scared I’d doze off while reading and wake up in flames.
  • “Clean” is a loosely held term for many candle and lantern fuel manufacturers. When I had a ton of fire light going, sometimes the house would smell a bit chemical-y. The best strategy is to assume you won’t be doing many things after sundown that require very much light. Do most of the dinner prep before sundown and save the bulk of cleaning for the morning. Trying to recreate electric light ends up requiring a ton of candles and lanterns. It’s better to have a small one in each room and a little cluster of them where you have a specific activity, such as in the kitchen for meal prep and then moving them over to the dining table while eating.
  • Using a sleep-tracking app, I noted that my average deep sleep increased by about 30% during this experiment. This made me think about what all those Netflix binges and late-night computer work sessions were doing to my brain.
  • The experiment's biggest surprise was that after returning to our usual nighttime routine, I still woke up very early. It’s been over a month since we’ve reintroduced electric light and I’m still waking up very early — regardless of when I go to bed. Those 21 days had a lasting effect on my internal clock.



Elijah Szasz

Elijah runs a LA/SLC creative agency focused on the good side of technology. He’s also a mediocre athlete, father, and entrepreneur. https://www.spark6.com/