OpenChronology Reference Implementation

The studio for
structured time

Author events in the open .chron format. Explore timelines spanning centuries. Share your record of history — freely, permanently, in a format that will outlast any platform.

Request early access View the standard →
The studio

Six tools.
One open standard.

Everything you need to create, explore, package, and verify chronological data — no proprietary lock-in, no code required.

01 — Author

Event Author

A guided form for crafting .chron files. No schema knowledge required — fill in what you know and export a valid, independently-citable event file in seconds. Every field beyond the title is optional.

Coming soon
02 — Visualize

Timeline Viewer Gallery

Not one viewer, but many — a curated set of reference implementations demonstrating the range of experiences possible from the same .chron data. Horizontal, vertical, radial, ledger. The standard is renderer-agnostic.

Coming soon
03 — Validate

Validator

Paste or drop any .chron, .chroncal, .chronverse, or .chronpkg file and get instant schema feedback from schemas.openchronology.org. Four severity levels. Exportable report.

Coming soon
04 — Package

Timeline Packager

Pack a collection of .chron files into a portable .chronpkg bundle — or unpack an existing bundle to inspect its events. Drag-and-drop interface, manifest preview, no code required.

Coming soon
05 — Calendars

Calendar Builder

Define a custom calendar system and export a .chroncal file. Name your months, set your epoch, describe your year length and intercalation rules. Reusable across any .chron file that references it.

Coming soon
06 — Universes

World Builder

Define a fictional or alternative universe and export a .chronverse file — canon scope, physics anchors, timeline frame. Built for novelists, game designers, and worldbuilders who need structured, shareable lore.

Coming soon
The standard is renderer-agnostic

One format,
infinite views

The OpenChronology standard defines how events are stored, not how they are displayed. These four conceptual implementations show the range of experiences possible from the same .chron data — each a different answer to the same question.

Horizon

The classic. A horizontal axis with significance-scaled dots and alternating above/below labels. Ideal for historical spans.

Codex

Vertical narrative. Events unfold like pages in a book — a natural fit for biography, story arcs, and sequential history.

Ledger

Tabular and data-forward. Sortable, filterable, dense. Built for researchers who need the full record at a glance.

Sphere

Radial and cyclical. Designed for fictional universes, custom calendars, and events measured in orbits rather than years.

These are conceptual implementations — Chronology Studio is one reference among many. All parser libraries and community-built viewer implementations are catalogued at openchronology.org/libraries. The standard is open; the ecosystem belongs to everyone.

Powered by OpenChronology

An open standard
for an open record

Chronology Studio is one reference implementation of the OpenChronology specification. Every .chron file you create is portable, independently citable, and readable by any conforming tool — today, and for as long as JSON endures.

openchronology.org → Schema registry →
File format family
.chron
Event File
A single portable event, era, or marker
.chroncal
Calendar
Reusable calendar system definition
.chronverse
Universe
Universe definition with canon scopes
.chronpkg
Bundle
ZIP collection of events and assets
.chronstream
Feed
NDJSON stream for APIs and exports
● apollo-11-moon-landing.chron
{ "meta": { "schema_version": "0.3", "canonical_url": "https://history.example.com/ events/moon-landing.chron" }, "event": { "id": "urn:uuid:8b4f1c2a-...", "content": { "title": "Apollo 11 Moon Landing", "description": "First crewed lunar landing. Astronauts Armstrong and Aldrin landed in the Sea of Tranquility." }, "temporal": { "start_value": "1969-07-20", "precision": "day", "calendar": "gregorian" }, "significance": { "level": "5" // civilizational }, "geographic_scope": "global" } }
Featured demonstration dataset

A thousand years,
precisely documented

The 1000 Year Project — anchoring OpenChronology at 1000yearproject.org — serves as the featured demonstration dataset for Chronology Studio. History from 1000 to 2000 CE, structured in open .chron format, with significance levels from local milestones to civilizational events.

1000-year-project.chronpkg — Horizon Viewer (preview)
Early Access

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to use the studio

Chronology Studio is under active development. Leave your email and we'll notify you when the first tools are ready to use.

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