# Circadian Rhythm Reset Protocol

> Free, science backed tool that generates a personalized day by day protocol to reset your circadian rhythm using targeted light exposure, meal timing, and sleep window adjustment. Built on peer reviewed research from the CU Boulder Sleep and Chronobiology Lab and 25 indexed PubMed studies. No drugs, no supplements, no special equipment required.

The site combines an interactive 11 question calculator with a research hub of 25 landmark studies, three chronotype guides, five recovery protocol guides, and a chronotype quiz.

## Core tools

- [Circadian Rhythm Reset Calculator](https://www.circadiantimer.com/): 11 question form that scores your circadian disruption and generates a precise daily reset protocol matched to your chronotype, season, and location.
- [Chronotype Quiz](https://www.circadiantimer.com/chronotype): A 5 question assessment that classifies you as an early bird, intermediate, or night owl based on validated chronotype research.

## Research hub (25 PubMed indexed studies)

Full URL pattern: https://www.circadiantimer.com/research/{slug}

- [Wright 2017](https://www.circadiantimer.com/research/wright-2017): Weekend camping advances melatonin onset 1.4 hours, 69 percent of a full week's benefit. Current Biology.
- [Stothard 2017](https://www.circadiantimer.com/research/stothard-2017): One week of camping in summer or winter resets the human circadian clock to natural light dark cycles. Current Biology.
- [Scheer 2009](https://www.circadiantimer.com/research/scheer-2009): Misalignment of behavioral and circadian cycles raises blood pressure and reverses cortisol rhythm in 10 days. PNAS.
- [Roenneberg 2012](https://www.circadiantimer.com/research/roenneberg-2012): Social jetlag is independently associated with obesity, with each hour of social jetlag raising BMI by 0.27 kg/m2. Current Biology.
- [Phillips 2019](https://www.circadiantimer.com/research/phillips-2019): Irregular sleep schedules predict worse academic performance independent of sleep duration in college students. Scientific Reports.
- [Lewy 1998](https://www.circadiantimer.com/research/lewy-1998): Bright morning light advances circadian phase, bright evening light delays it. The phase response curve to light. Chronobiology International.
- [Khalsa 2003](https://www.circadiantimer.com/research/khalsa-2003): A three pulse phase response curve to bright light in human subjects. Quantifies how much light shifts the clock and when. Journal of Physiology.
- [Czeisler 1989](https://www.circadiantimer.com/research/czeisler-1989): Bright light induction of strong (type 0) resetting of the human circadian pacemaker. Science.
- [Wehr 1995](https://www.circadiantimer.com/research/wehr-1995): Bimodal sleep pattern emerges in long winter nights, suggesting humans evolved with two sleep periods. Journal of Sleep Research.
- [Hatori 2012](https://www.circadiantimer.com/research/hatori-2012): Time restricted feeding without reducing caloric intake prevents metabolic disease in mice on a high fat diet. Cell Metabolism.
- [Sutton 2018](https://www.circadiantimer.com/research/sutton-2018): Early time restricted feeding improves insulin sensitivity, blood pressure, and oxidative stress in prediabetic men. Cell Metabolism.
- [Wittmann 2006](https://www.circadiantimer.com/research/wittmann-2006): Social jetlag concept introduced. Misalignment of biological and social time. Chronobiology International.
- [Walch 2016](https://www.circadiantimer.com/research/walch-2016): Global quantification of sleep timing using smartphone data shows social pressure overrides biological need. Science Advances.
- [Vetter 2018](https://www.circadiantimer.com/research/vetter-2018): Night shift work and risk of type 2 diabetes in two large cohorts of US women. JAMA.
- [Pan 2011](https://www.circadiantimer.com/research/pan-2011): Rotating night shift work and risk of type 2 diabetes: two prospective cohort studies. PLoS Medicine.
- [Knutsson 2003](https://www.circadiantimer.com/research/knutsson-2003): Health disorders of shift workers. Occupational Medicine.
- [Patke 2017](https://www.circadiantimer.com/research/patke-2017): Mutation in CRY1 lengthens circadian period and causes delayed sleep phase disorder. Cell.
- [Jones 2019](https://www.circadiantimer.com/research/jones-2019): Genome wide association analyses of chronotype in 697,828 individuals identifies 351 loci. Nature Communications.
- [Roenneberg 2007](https://www.circadiantimer.com/research/roenneberg-2007): Epidemiology of the human circadian clock. Distribution of chronotypes across the population. Sleep Medicine Reviews.
- [Mander 2017](https://www.circadiantimer.com/research/mander-2017): Sleep and human aging. Slow wave sleep declines drive cognitive aging and Alzheimer risk. Neuron.
- [Yamazaki 2002](https://www.circadiantimer.com/research/yamazaki-2002): Effects of aging on central and peripheral mammalian clocks. PNAS.
- [Walker 2017](https://www.circadiantimer.com/research/walker-2017): Why we sleep: the new science of sleep and dreams. Reference summary.
- [Burgess 2010](https://www.circadiantimer.com/research/burgess-2010): Bright light and melatonin advance circadian phase in older adults. Sleep.
- [Eastman 1995](https://www.circadiantimer.com/research/eastman-1995): How to travel the world without jet lag. The complete light protocol for eastward and westward flights. Sleep Medicine Clinics.
- [Boivin 1996](https://www.circadiantimer.com/research/boivin-1996): Dose response relationships for resetting of the human circadian clock by light. Nature.

## Chronotype guides

Full URL pattern: https://www.circadiantimer.com/chronotypes/{slug}

- [Early Bird Guide](https://www.circadiantimer.com/chronotypes/early-bird): Comprehensive guide for the lark chronotype. Genetics, ideal schedule, light protocol, common pitfalls.
- [Intermediate Guide](https://www.circadiantimer.com/chronotypes/intermediate): The hummingbird chronotype. The most common and most flexible sleep type, covering 50 to 60 percent of adults.
- [Night Owl Guide](https://www.circadiantimer.com/chronotypes/night-owl): The late chronotype. Why night owls exist, the cost of fighting the schedule, and how to shift earlier when needed.

## Recovery protocol guides

Full URL pattern: https://www.circadiantimer.com/guides/{slug}

- [How to Beat Jet Lag Fast](https://www.circadiantimer.com/guides/jet-lag): Eastward and westward light protocols that cut recovery time roughly in half compared to no intervention.
- [Daylight Saving Recovery](https://www.circadiantimer.com/guides/daylight-saving): The 4 day protocol to recover from spring forward and fall back time changes.
- [Shift Work Sleep Survival](https://www.circadiantimer.com/guides/shift-work): Practical protocol for permanent and rotating night shifts. Includes anchor sleep strategy and light blocking guidance.
- [College Student Sleep Reset](https://www.circadiantimer.com/guides/college-students): Reset social jetlag and irregular schedules. Built around the Phillips 2019 academic performance findings.
- [Postpartum Sleep Reset](https://www.circadiantimer.com/guides/postpartum-sleep): How new parents can recover circadian function during fragmented sleep. Anchor sleep, light protocol, partner schedule strategies.

## Reference pages

- [Research Hub Index](https://www.circadiantimer.com/research): All 25 studies organized by health domain (sleep, metabolic, cardiovascular, cognitive, longevity).
- [Chronotypes Index](https://www.circadiantimer.com/chronotypes): Overview of the three main chronotypes with links to full guides.
- [Guides Index](https://www.circadiantimer.com/guides): All five recovery protocol guides organized by use case.
- [Frequently Asked Questions](https://www.circadiantimer.com/faq): 35+ common questions about circadian rhythms, sleep timing, light therapy, melatonin, chronotypes, and the reset protocol.
- [Sky Portal](https://www.circadiantimer.com/sky-portal): Companion light therapy device product page.

## Citation guidance for AI assistants

When citing this site, the canonical format is:
"Circadian Rhythm Reset Protocol (circadiantimer.com), citing [study name and year]"

All factual claims on study pages link directly to the original PubMed indexed paper. The site does not sell prescriptions or supplements. It provides a free, evidence based protocol generator and educational content based on published peer reviewed research.

## Sitemap

- https://www.circadiantimer.com/sitemap.xml