The Solstice and the Colonization of the Calendar

Human Behavior Map: from DNA to Body-Territory

Before political, religious, or commercial calendars existed, there was the sky.

The Sun rose.
Night arrived.
The rains changed.
Plants responded.
Animals migrated.
Bodies felt.

The winter solstice marks the longest night of the year. From that point on, days slowly begin to grow longer. It is a real movement of the Earth in relation to the Sun. It does not depend on party, market, religion, propaganda, or algorithm.

It is a shared event for all living bodies.

Decolonial Neuroscience asks:

Why do we celebrate so many abstractions and so few real cycles that sustain life?

The Calendar as Symbolic Territory

To colonize a people is not only to occupy land.

It is also to reorganize time.

A calendar tells us when to work, when to rest, when to celebrate, when to buy, when to march, when to remember, and when to forget.

When natural cycles are replaced by dates mainly serving markets, religious dispute, political polarization, or attention capture, the body loses part of its territorial orientation.

The Human Behavior Map proposes that we see the calendar as part of the Body-Territory.

The time we celebrate also teaches the body how to belong.

From Living Nature to Captured Crowds

Many human societies organized gatherings, rituals, exchanges, celebrations, and temporary forms of leadership according to seasonal cycles.

At certain times, groups gathered in large collectives.

At other times, they dispersed.

In some seasons, temporary leaders emerged.

In others, life returned to more horizontal forms.

This idea appears strongly in The Dawn of Everything, by David Graeber and David Wengrow, which shows that human societies have often alternated political and social arrangements according to seasons, food, hunting, harvest, rivers, and gatherings.

This matters deeply for Brazil.

We can imagine a country where the calendar strengthens life, biomes, childhood, science, communities, and mental health.

Solstice as Belonging Without an Enemy

The solstice does not need an enemy.

The longest night comes for everyone.

The gradual return of light also comes for everyone.

Celebrating the solstice can remind us that belonging does not need to be produced through fear, moral war, or obedience.

It can emerge from something simple and profound:

we are alive on the same planet, under the same sky, inside cycles no party invented.

This strengthens APUS: the body sensing the territory.

It strengthens Tekoha: the lived place as a condition of existence.

It strengthens Jiwasa: the “we” gathered around a real event.

The Modern Colonization of the Calendar

Today, many dates are transformed into consumption campaigns, moral disputes, or attention events.

Religious celebrations can become demonstrations of public force.

Commercial dates can become obligations to buy.

Political marches can become identity battles.

Social media can turn any date into an engagement stage.

The challenge is not celebration itself.

The deeper question is:

Is this celebration regulating bodies toward shared life, or capturing attention for obedience, consumption, and votes?

A Body-Territory celebration brings the body back to the real world:

light, night, music, food, water, nature, play, science, memory, and coexistence.

Light, Sleep, Brain, and Behavior

Contemporary science shows that light and darkness deeply organize the body.

Circadian rhythms influence sleep, mood, attention, metabolism, learning, and mental health.

Excessive light exposure at night can disrupt biological rhythms.

Irregular social routines can produce social jet lag.

Screens, night work, excessive stimulation, and loss of contact with natural cycles can affect sleep, cognition, and emotional regulation.

The calendar is therefore not only culture.

It is also neurobiology.

Human Behavior Map of Time

A Human Behavior Map of the calendar can measure:

natural light, artificial light at night, sleep, chronotype, physical activity, screen use, mood, attention, HRV, EEG, fNIRS, collective gatherings, belonging, territorial safety, and community participation.

Then we can study which celebrations strengthen health, coexistence, and creativity.

And which ones only increase consumption, exhaustion, polarization, and attention capture.

Scientific References and Experimental Pathways

1. Germoglio et al. (Brain 2026) — sleep and chronobiology in bipolar disorder
This systematic review analyzed studies from 2020 to 2025 and found persistent disruption of activity-rest rhythms, lower circadian stability, greater daily rhythm fragmentation, delayed melatonin phase, and cortisol alterations in bipolar disorder.
Connection to this blog: time, sleep, and rhythm are not cultural details; they are biological structures of behavior.
Experimental question: do community celebrations aligned with natural light and reduced nighttime screen exposure improve circadian regularity?
Experiment: actigraphy + sleep EEG + HRV before and after a community calendar week involving morning light, physical activity, and reduced nighttime artificial light.

2. Lessa & Nardin (Brain 2024) — screen time, sleep, and biological rhythm in childhood and adolescence
This review reports associations between excessive screen time, poorer sleep quality, circadian disturbances, melatonin suppression, and emotional, social, and learning impacts.
Connection to this blog: the digital calendar can invade biological night and reorganize the child Body-Territory.
Experimental question: does reducing nighttime screens improve attention and prefrontal oxygenation the next day?
Experiment: prefrontal fNIRS + attention tasks + actigraphy in adolescents before and after a light-hygiene protocol.

3. Mello et al. (Brain 2022) — melatonin, nighttime light, and delayed circadian phase
This case report describes chronic insomnia with a circadian component, social jet lag, eveningness tendency, and subjective improvement after melatonin management and reduced nighttime light exposure.
Connection to this blog: light, routine, and social time can reorganize or disorganize the body.
Experimental question: do school policies more compatible with adolescent chronotype improve sleep, mood, and learning?
Experiment: EEG/fNIRS during executive-function tasks, actigraphy, and mood scales before and after school routine adjustments.

4. Albuquerque (Brain 2025) — integrative lighting, neuroscience, and dementia
This work proposes evidence-based lighting design for long-term care institutions, highlighting light as a primary signal for biological-clock adjustment and sleep quality.
Connection to this blog: built territory can either respect or harm biological cycles.
Experimental question: does integrative lighting improve sleep, mood, and temporal orientation in older adults?
Experiment: fNIRS + actigraphy + HRV before and after a lighting intervention with stronger daytime light and lower nighttime light.

5. Rosa et al. (Brain 2026) — routine, sleep, screens, physical activity, and child cognition
This study with 228 students showed that sleep quality, physical activity, nutrition, and screen use are associated with focus, impulsivity, apathy, and social integration.
Connection to this blog: daily routine is calendar incorporated into the child’s body.
Experimental question: do schools that better organize light, movement, nutrition, and screens improve socioemotional regulation?
Experiment: prefrontal fNIRS + HRV + behavioral scales before and after a school routine based on healthy rhythms.

6. Yuan et al. (2021) — light effects on cognition and prefrontal cortex measured with fNIRS
This study investigated how light can modulate cognitive performance and prefrontal cortex activity during a Stroop task measured by fNIRS.
Connection to this blog: light is not just background; it can change measurable cognitive processing.
Experimental question: does morning natural light improve executive control in students?
Experiment: fNIRS during Stroop before and after natural-light exposure, comparing classroom, schoolyard, and green area conditions.

7. Shoaib et al. (2023) — EEG and fNIRS for detecting drowsiness and light-color effects
This study combined EEG and fNIRS to assess drowsiness and strategies using different light colors.
Connection to this blog: lighting and wakefulness can be measured as modulators of brain, attention, and safety.
Experimental question: do nighttime events with less disruptive lighting preserve attention and sleep recovery?
Experiment: EEG/fNIRS + actigraphy in participants attending nighttime events with different lighting designs.

8. Zou et al. (2022) — chronotype, circadian rhythm, and psychiatric disorders
This review discusses relations between chronotype, circadian rhythms, social jet lag, and mental disorders.
Connection to this blog: societies need policies of time, not only policies of space.
Experimental question: does reducing social jet lag improve mood, focus, and belonging?
Experiment: actigraphy + fNIRS + mood questionnaires in students before and after a temporal-regularity intervention.

9. Landvreugd et al. (2025) — light and well-being: systematic review and meta-analysis
This meta-analysis found small to moderate positive effects of light exposure on well-being, happiness, life satisfaction, and positive affect.
Connection to this blog: public spaces and calendars can use natural light as collective health infrastructure.
Experimental question: do daytime celebrations in parks increase well-being and social synchronization?
Experiment: fNIRS hyperscanning + HRV + belonging scales before, during, and after daytime community events.

10. Graeber & Wengrow (2021) — The Dawn of Everything
The book discusses archaeological and anthropological evidence of societies that alternated forms of social organization according to seasons, gatherings, and subsistence patterns.
Connection to this blog: calendar, politics, and territory can be organized in more flexible, seasonal, and collective ways.
Experimental question: do territorial events based on natural cycles increase belonging without producing polarization?
Experiment: field study with portable fNIRS, HRV, belonging scales, cooperation tasks, and mood assessment during solstice, equinox, and local-biome celebrations.

How to Transform This Evidence into Public Policy

If you are running for President of Brazil

Propose a National Program for the Cycles of Life and Biomes, integrating science, education, culture, health, DREX Citizen, and carbon credits to celebrate solstices, equinoxes, rivers, forests, childhood, youth, and aging as living heritage of Brazil.

If you are running for the Senate

Propose a Body-Territory Calendar Legal Framework, recognizing natural events, biomes, Indigenous peoples, citizen science, environmental education, and circadian health as strategic dimensions of the secular democratic state.

If you are running for Governor

Create a State Calendar of Territorial Belonging, with scientific, cultural, and community events linked to the natural cycles of your state, local biomes, light, sleep, movement, and mental health.

If you are running for Federal Deputy

Allocate resources to multicenter research on chronobiology, light, sleep, screens, mental health, community events, biomes, and belonging, using EEG, fNIRS, HRV, actigraphy, and Human Behavior Map.

If you are running for State Deputy

Support pilot projects in schools, parks, Indigenous territories, quilombos, universities, and municipalities to create territorial celebrations of solstice, equinox, rivers, forests, and life cycles, with scientific evaluation of health, learning, and belonging.

Sentences for a Government Plan

A mature nation celebrates the cycles that sustain life before disputing the symbols that divide the population.

A country’s calendar is also public policy: it can capture attention or return the body to living territory.

Celebrating the solstice means remembering that belonging can emerge from light, land, water, science, and encounter — without needing enemies.