Author: James Good

Major Milestones In Earth’s Past, Present & Future Using Earth Planetary Era (EPE)

Written by James Good
Date: 4.54/075-12-30 EPE (30/12/2025 CE)

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Framing Note

All dates in this post are expressed using authoritative Earth Planetary Era (EPE) values, as defined in the Planetary Era Time System – Technical Specification v1-00.

• 0 EPE corresponds to Earth’s formation.
• 4,540,000,000 EPE corresponds to 1950-01-01 CE (the scientific “present”).
• 4,540,000,075 EPE corresponds to 2025 CE.

Deep-time events are inherently uncertain and are therefore presented as ranges.
This is a planetary-scale timeline, not a year-accurate chronology.

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Earth’s Evolutionary Milestones

🌍 Earth Forms

0 EPE

Earth forms through accretion in the early Solar System.
This event defines the epoch of Earth Planetary Era.

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🌕 Moon-Forming Impact

~20,000,000 – 60,000,000 EPE

A giant impact between the early Earth and a Mars-sized body results in the formation of the Moon, stabilising Earth’s axial tilt and influencing long-term climate behaviour.

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🌊 Stable Crust & Long-Lived Oceans

~100,000,000 – 300,000,000 EPE

Earth cools sufficiently to maintain a stable crust and persistent liquid oceans.
Surface conditions become continuously habitable.

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🧬 Earliest Evidence Of Life

~700,000,000 – 1,100,000,000 EPE

Simple microbial life appears, likely in marine environments.
Life emerges relatively early in Earth’s history.

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🌫️ Great Oxidation Event

~2,100,000,000 – 2,400,000,000 EPE

Photosynthetic organisms dramatically increase atmospheric oxygen, permanently altering Earth’s chemistry and enabling complex metabolism.

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🧫 First Eukaryotic Cells

~2,600,000,000 – 2,900,000,000 EPE

Cells with nuclei appear, allowing for much greater biological complexity.

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🐚 Cambrian Diversification

~3,990,000,000 – 4,010,000,000 EPE

A rapid diversification of multicellular life occurs.
Most major animal body plans appear over a geologically brief interval.

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🌱 Life Moves Onto Land

~4,060,000,000 – 4,080,000,000 EPE

Plants, followed by arthropods and vertebrates, colonise land.
Terrestrial ecosystems begin reshaping the planet.

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🦖 Dinosaurs Dominate

~4,300,000,000 – 4,474,000,000 EPE

Dinosaurs emerge and dominate terrestrial ecosystems for over 160 million years.

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☄️ K–Pg Mass Extinction

~4,474,000,000 EPE

A large asteroid impact triggers a global mass extinction.
Non-avian dinosaurs disappear; mammals diversify.

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Human History In Planetary Context

🦍 Earliest Hominins

~4,533,000,000 – 4,534,000,000 EPE

Bipedal human relatives appear in Africa.
From a planetary perspective, this occurs extremely late.

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🧍 Emergence Of Genus Homo

~4,537,000,000 – 4,538,000,000 EPE

Tool-using humans emerge.
Fire use, language, and culture develop gradually.

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🌾 Agriculture

~4,539,988,000 EPE

Humans begin farming and forming permanent settlements.
Civilisation appears in the final fraction of Earth’s timeline.

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🏭 Industrial Civilisation

~4,539,999,800 – 4,540,000,000 EPE

Industrialisation, fossil fuel use, and rapid technological acceleration begin.
Human activity becomes a geological force.

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🚀 Space & Digital Age

~4,540,000,000 – 4,540,000,075 EPE

Satellites, global communication, computing, and artificial intelligence emerge.
Humanity begins to leave Earth and reflect on its planetary impact.

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📍 Present Day

4,540,000,075 EPE

All of recorded human history occupies a near-invisible slice at the very end of Earth’s planetary timeline.

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Earth’s Long-Term Trajectory

☀️ Increasing Solar Luminosity

~5,040,000,000 – 5,140,000,000 EPE

The Sun gradually brightens, destabilising Earth’s climate.
Complex life becomes increasingly difficult to sustain.

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🌊 Loss Of Earth’s Oceans

~5,540,000,000 – 5,840,000,000 EPE

Rising temperatures lead to ocean evaporation and atmospheric water loss.
Earth becomes uninhabitable for known life.

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🧫 End Of Complex Life

~5,600,000,000 – 6,000,000,000 EPE

Only microbial or extremophile life may persist, if any.

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🔥 Sun Becomes a Red Giant

~8,540,000,000 – 9,040,000,000 EPE

The Sun expands dramatically.
Inner planets are destroyed or rendered unrecognisable.
Earth, if it survives at all, is no longer Earth.

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⚪ White Dwarf Remnant

~9,140,000,000+ EPE

The Sun sheds its outer layers and stabilises as a cooling white dwarf.
The Solar System enters a long, quiet decline.

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Closing Perspective

Seen through the Earth Planetary Era:

• Life is ancient but fragile
• Complex life is temporary
• Humanity is extraordinarily recent
• The future arrives very quickly

Civilisation occupies a geological instant – but an instant with consequences that may echo for billions of years.

The value of a planetary timeline is not humility for its own sake.
It is clarity.

Technical Specification v1-00

Author: James Good
Date: 4.54/075-12-30 EPE (30/12/2025 CE)

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The specification is designed to coexist with existing civil calendars, remain compatible with scientific & computational systems, and scale naturally to a multi-planet civilisation.

This document defines the Planetary Era (PE) time system: a non-religious framework for civil timekeeping anchored to physical events rather than cultural or theological reference points.

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Purpose & Design Goals

The Planetary Era system is designed to provide:

• a non-religious civil timekeeping framework
• anchoring to physical events rather than cultural or theological ones
• compatibility with existing civil calendars
• scalability to multiple planets
• interoperability with scientific & computational systems

The system is explicitly designed for coexistence, not replacement.

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System Hierarchy

The framework consists of three conceptual layers.

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Universal Physical Era (UPE)

UPE allows time on different planets to be referenced back to a common universal origin, much like a coordinate system in physics.

Definition: Time measured relative to the formation of the universe
Epoch: Big Bang (~13.8 billion years ago)
Purpose: Universal physical reference frame

UPE is:

• planet-independent
• culture-independent
• not intended for daily civil use

UPE exists to provide a common reference layer across planetary systems.

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Planetary Era (PE)

Definition: A class of civil timekeeping systems
Anchor: Formation of a specific planetary body
Purpose: Local civil time, interoperable via UPE

PE is a template, not a single calendar.

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Earth Planetary Era (EPE)

Definition: Planetary Era instance for Earth
Formal Identifier: SOL-EAR-PE
Human-Friendly Short Form: EPE
Anchor: Earth’s formation
Purpose: Civil timekeeping on Earth

This specification primarily defines Earth’s Planetary Era, while remaining extensible to other bodies.

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Epoch Definition (EPE)

Scientific Reference Point (“Present”)

In geoscience, “present” is formally defined as:

1950-01-01 00:00:00 UTC

This definition is fixed and internationally accepted in:

• radiocarbon dating
• geology
• archaeology

All BP (Before Present) values refer to this reference point, not to the current date.

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Earth Formation

Earth’s formation is constrained by radiometric dating to approximately:

4.54 × 10⁹ years before present (BP)

This value carries acknowledged uncertainty on the order of tens of millions of years.

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EPE Epoch

The Earth Planetary Era epoch is defined as:

EPE 0 = Earth formation

Which corresponds to:

1950-01-01 = 4,540,000,000 EPE

This mapping is exact by definition.

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EPE Conversion Rules

For a Gregorian calendar year Y CE, ignoring month & day precision:

EPE ≈ 4,540,000,000 + (Y − 1950)

For an event occurring X years before present (BP):

EPE ≈ 4,540,000,000 − X

Where “present” is defined as 1950-01-01 00:00:00 UTC.

When full date & time precision is used, the mapping between Gregorian time and EPE is exact by definition.

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Time Units & Calendar Structure

Units

EPE retains all existing civil units:

• second
• minute
• hour
• day
• month
• year

No new units are introduced.

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Year Length

An EPE year is identical to a Gregorian year:

~365.2422 Earth days

This ensures:

• seasonal continuity
• legal compatibility
• software compatibility

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Calendar Structure

• Gregorian months
• Gregorian leap-year rules
• UTC as the reference time standard

No structural calendar changes are introduced.

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Year Numbering

Authoritative EPE Year

The authoritative representation of an EPE year is a monotonic, non-negative integer:

YYYYYYYYYY EPE

Example (30 December 2025 CE):

4,540,000,075 EPE

Authoritative EPE values:

• are authoritative for computation
• are sortable
• are unambiguous
• are continuous

Authoritative EPE values shall never be negative.

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Shorthand Human-Readable Form

A compact shorthand may be used for contemporary civil contexts only:

4.54/075 EPE

Where:

• 4.54 = Earth’s age in billions of years, rounded to two decimal places
• 075 = year index within the current million-year block (000–999)

The shorthand representation is display-only & not authoritative.

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Minimal Spoken Form

For speech & informal writing:

75 EPE

This mirrors existing civil conventions.

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Representation Rules By Timescale

The two representations serve different purposes & are not interchangeable.

Context	Representation
Deep geological / planetary history	Authoritative EPE only
Modern history	Authoritative EPE or dual-dated
Contemporary civil use	Shorthand permitted

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Mandatory Authoritative Usage For Deep Time

When discussing:

• planetary formation
• evolution of life
• mass extinctions
• palaeoclimate
• deep future projections

Only authoritative EPE values shall be used.

Example:

Dinosaur extinction: ~4,474,000,000 EPE

Shorthand representations must not be used for such events.

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Shorthand Constraints

The shorthand suffix:

/YYY

• shall always be an integer
• shall range from 000 to 999
• shall increment once per civil year
• shall not contain fractional values

Fractional shorthand values (e.g. /999.5) are explicitly disallowed.

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Dates Before 1950

Dates earlier than 1950-01-01 are represented by simple subtraction.

Gregorian Year	EPE Year
1950	4,540,000,000 EPE
1949	4,539,999,999 EPE
1900	4,539,999,950 EPE

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Shorthand For Pre-1950 Dates

Signed shorthand offsets may be used for display purposes:

4.54/-001 EPE   (1949)
4.54/-050 EPE   (1900)

Negative values are permitted only in shorthand offsets; authoritative EPE values remain non-negative.

This approach avoids BC/AD discontinuities.

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Date Formatting (Interoperability)

Authoritative Date Format

Machine-readable dates shall follow ISO-style ordering:

YYYYYYYYYY-MM-DD EPE

Example:

4540000075-12-30 EPE

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Date-Time Format

Including time & timezone:

4540000075-12-30T03:05Z EPE

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Display Formats

Human-facing formats may vary but must not be ambiguous.

Recommended display format:

4.54/075-12-30 EPE

Locale-specific variants (e.g. 30/12) are display-only.

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Multi-Planet Extension

Each planetary body defines a Planetary Era instance with both a formal ISO-style identifier and an optional human-friendly shorthand.

Body	Formal Identifier	Short Form
Earth	SOL-EAR-PE	EPE
Mars	SOL-MAR-PE	MaPE
Mercury	SOL-MER-PE	MePE
Moon	SOL-LUN-PE	LPE
Venus	SOL-VEN-PE	VPE

Each instance:

• anchors to planetary formation
• uses the body’s local orbital year
• remains interoperable via UPE

Cross-planet comparison shall be performed via UPE, not by equating local year lengths.

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AI & Computational Considerations

The Planetary Era framework:

• removes religious epochs
• provides monotonic timelines
• separates universal & local reference frames
• reduces semantic calendar conversion overhead

It does not change computational complexity or clock precision.

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Non-Goals

This specification explicitly does not:

• mandate adoption
• abolish existing calendars
• redefine seconds or clocks
• introduce a planet-neutral civil year
• claim cosmological precision beyond accepted uncertainty

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Timekeeping is a coordinate system.
This specification explores what happens when the zero-point is physical rather than cultural.

Why mention religion at all?

Because the current global civil calendar is numerically anchored to a religious event. Naming that fact is not an attack on belief; it is simply acknowledging the historical origin of a convention. The Planetary Era proposal does not seek to replace religious or cultural calendars used for worship or tradition — only civil and scientific timekeeping.

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How is Earth Planetary Era (EPE) different from geological units like Ma and Ga?

Ma (million years ago) and Ga (billion years ago) are measurement units, not calendars.

They describe how long ago something happened relative to the present, which means their values slowly change as time passes. For example, an event described as “66 Ma” today will be “66.001 Ma” a thousand years from now. Ma/Ga are excellent tools for studying the past, but they are inherently backward-looking and non-permanent.

The Earth Planetary Era (EPE) is different. It defines a forward-counting, absolute timeline anchored to a fixed physical event: Earth’s formation. Each event is assigned a permanent position on Earth’s lifespan that does not change over time.

In short:

• Ma/Ga measure duration (how long ago something happened)
• EPE identifies position (where an event sits in Earth’s history)

This makes EPE suitable for:

• past, present, and future events
• stable identifiers that never drift
• civil timekeeping
• long-term databases and AI systems
• extension to other planets via Planetary Era instances

EPE does not replace Ma/Ga in geology.
It provides a calendar-scale coordinate system that Ma/Ga were never designed to be.

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Why not just use the Big Bang as the calendar?

The Universal Physical Era (UPE) already does this. However, cosmological timescales are not suitable for daily human life. Planetary Era calendars sit one level below UPE, providing local civil time while remaining interoperable with a universal physical reference.

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Why use 1950 as a reference point?

In geoscience and radiocarbon dating, “present” is formally defined as 1950-01-01 UTC. This convention exists for practical scientific reasons and is internationally accepted. Using it ensures compatibility with existing geological and archaeological timekeeping and avoids introducing a new arbitrary reference.

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Isn’t Earth’s formation date uncertain?

Yes — within a narrow range. Earth’s age is constrained to approximately 4.54 billion years, with uncertainty of tens of millions of years. At civil or even geological timescales, this uncertainty is negligible. Importantly, the Planetary Era explicitly acknowledges uncertainty rather than hiding it behind mythology.

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Why keep the Gregorian calendar at all?

Because changing months, leap years, or clocks would break law, infrastructure, software, and daily life. The Planetary Era changes only the year numbering, preserving full compatibility with existing systems. This is a practical decision, not an ideological one.

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Why not start at the beginning of human civilisation?

That simply shifts the arbitrariness. Definitions of “civilisation” vary culturally and geographically, and many such systems quietly retain religious anchors beneath the surface. Planetary formation is a physically defined event that does not privilege any culture or species.

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Would this mean abandoning current calendars?

No. Like most standards, adoption would be incremental. Dual dating allows existing calendars to coexist while providing a physically anchored alternative for contexts where long-term thinking matters.

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Is this intended to be mandatory?

No. The Planetary Era is a proposed convention, not a decree. Its usefulness — or lack of it — will determine whether it is adopted.

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Why would anyone actually use this?

Because it removes an awkward cultural assumption, aligns better with scientific timescales, and offers a clearer sense of perspective. Unlike many calendar reforms, it does not require people to give anything up — only to see time slightly more honestly.

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Does this system help AI systems?

Yes, modestly and indirectly. AI systems already prefer explicit, monotonic, physically anchored time references. The UPE → PE → EPE hierarchy aligns civil timekeeping with how AI represents time internally, reducing ambiguity and the need for special-case conversions. This does not give AI new capabilities, but it simplifies long-horizon reasoning and interoperability.

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Does this reduce AI energy consumption?

Not directly. Training and running AI models is dominated by hardware and data movement costs. However, cleaner time representations reduce unnecessary conversions, explanations, and contextual inference. Each saving is small, but at scale they reduce wasted computation. The benefit is incremental, not transformational.

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What about different planets having different lengths of year?

That is expected, and the system is designed to accommodate it.

In the Planetary Era framework, the epoch (what year 0 represents) is separate from the length of a year. Each planet defines a year using its own physical orbital period around its star, exactly as Earth does today.

• EPE years are Earth years.
• MPE years are Martian years.

Civil calendars reflect local seasons and lived experience. When time must be compared across planets, both calendars are converted to UPE, which provides a common physical reference.

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Would this system make communication with non-human intelligences easier?

Potentially, yes – in a limited but meaningful way.

Any non-human intelligence capable of interstellar communication would need to understand physics, orbital mechanics, and cosmological timescales. A timekeeping system anchored to planetary formation and nested within a universal physical reference removes cultural and religious assumptions that would otherwise require explanation.

The goal is to minimise semantic overhead when explaining how humans locate themselves in time. In that sense, physically anchored timekeeping is more immediately legible than culture-based calendars.

Posted 4.54/075-12-29 EPA
Edited 4.54/075-12-30 EPA

It seems odd to me that modern civilisation still measures time based on a religious event.

The dominant global calendar – whether labelled AD (Anno Domini) or rebranded as CE (Common Era) – remains numerically anchored to the traditional date of the birth of Jesus. While this has deep historical and cultural roots, it is ultimately a theological reference point that persists by convention rather than necessity.

Calendars are practical tools, so most people accept this without complaint. But as our challenges increasingly span geological timescales, planetary boundaries, and potentially multiple inhabited worlds, the limitations of religion-anchored timekeeping become harder to ignore.

If we were designing a calendar today from first principles — without religion, culture, or human privilege – what would we choose?

Calendar Based on Science, Not Belief

A non-religious calendar needs a physical anchor: an event that predates humanity and belongs to no culture.

At the largest scale, such an anchor already exists – the formation of the universe itself.

Cosmology places this event at approximately 13.8 billion years ago, with well-characterised uncertainty. This provides a natural root reference for all timekeeping, independent of planets, species, or human civilisations.

This root frame could be called the Universal Physical Era (UPE).

UPE is not intended for everyday use. It functions as a universal reference layer – analogous to absolute coordinates in physics – allowing any local calendars to be related without privileging any one world or culture.

Planetary Era (PE) – Globally Consistent Local Civil Time

Humans don’t live at cosmological scales. Civil calendars must remain local, practical and familiar.

From UPE, we can derive an entire family of Planetary Era (PE) calendars, each anchored to the formation of a specific planet and used for that planet’s local civil time.

Earth Planetary Era (EPE)

For Earth, the physical anchor is well established.

Radiometric dating of meteorites, lunar samples, and the oldest terrestrial minerals consistently places Earth’s formation at approximately 4.54 billion years ago.

Geoscience already measures time this way using ‘years before present’, where “present” is formally defined as 1950-01-01 00:00:00 UTC – an internationally accepted scientific convention adopted for practical, not cultural, reasons.

The Earth Planetary Era (EPE) simply extends this existing scientific framework into civil timekeeping.

Definition (EPE):

• Epoch: Earth’s formation, defined as 4.54 × 10⁹ years before 1950-01-01 00:00:00 UTC.
• Units: seconds, days, months, and years unchanged.
• Calendar structure: Gregorian, for full compatibility.

Nothing about clocks, leap years, or months changes. Only the year numbering does.

So, What Year is it Now?

Late 2025 corresponds to 4,540,000,075 EPE.

But that wouldn’t be practical for use day-to-day. So a shorthand display format would be used… 4.54/075 EPE.

‘4.54’ represents Earth’s age in billions of years and ‘075’ is the current year within the present million-year block.

In speech and casual writing, the minimal form works exactly like existing usage… “75 EPE” or “seventy-five Earth Planetary Era”.

Why Perspective Matters

Calendars do more than just organise social schedules – they help shape perspective.

Anchoring time to a religious or cultural event reinforces:

• Short-term horizons.
• Human centrality.
• The assumption that civilisation sits near the centre of history.

Anchoring time to a 4.5-billion-year-old planet, nested within a 13.8-billion-year-old universe, places human history where it belongs: recent, fragile, and contingent.

This is not symbolism. It aligns civil timekeeping with:

• Geological and climate timescales.
• Established scientific practice.
• AI systems that already operate on absolute timelines.
• Long-term thinking about planetary stewardship.

A Calendar System that Scales Beyond Earth

A multi-planetary civilisation cannot continue to remain Earth-centric.

The Planetary Era model scales naturally:

• EPE — Earth Planetary Era
• MPE — Mars Planetary Era
• VPE (Venus), LPE (Lunar), and others as required…

Each planet uses its own formation-anchored civil calendar for local life, while all remain interoperable through UPE as a universal physical reference.

No calendar reset is required when humans leave Earth.

Adoption Through Coexistence

This is not a call to abolish existing calendars.

Like most successful standards, adoption would begin quietly through dual dating:

1 January 2026 (76 EPE)

Unlike many calendar reforms, this proposal does not ask people to abandon familiar structures – only to remove a cultural assumption that many already feel uneasy about, while gaining a clearer sense of scale in return.

A Simple Hierarchy for a New Calendar System

• UPE – universal physical time
• PE – a class of planet-anchored civil calendars
• EPE, MPE, … – local instances for other worlds

No religion. No privilege bias. No reset required ever!

Just science, applied consistently.

This proposal is offered as a practical convention. Its usefulness will determine whether it survives the test of time!

Proposed by James Good
Date: 4.54/075-12-29 (29/12/25)