Public evidence summary reviewed: June 2026

Evidence and sources

Check the public source pages behind the main facts on the calendar.

Sources checked for these facts

The source links are grouped by the calendar month where each fact appears. More sources can be added without turning this page into one long list.

Calendar facts
6
Checked links
12
Reviewed
June 2026
Symbol key

Marker shapes repeat the meaning in text so the calendar does not rely on colour alone.

  • Filled dot

    A main date used to hold the story in place.

  • Ring dot

    The event is accepted, but the date or placement is rounded.

  • Large filled dot

    A major story moment, such as dinosaurs arriving late in the year.

  • Small filled dot

    Many events are squeezed into a tiny part of the calendar.

Source browser

Choose a month to see the calendar facts and source pages used for that part of the exhibit.

6 facts / 12 links

Calendar month

January

1 fact / 1 source link

  • 1st 00:00:00

    Big Bang

    well-supported date

    The calendar begins with the Big Bang so an enormous story can fit into one familiar year.

    • NASA Space Place

      What Is the Big Bang?

      This NASA page explains the Big Bang and the age used for the calendar.

      Supports: the universe is about 13.8 billion years old Calendar: January 1st, 00:00:00 well-supported date

      Open source

Calendar month

September

2 facts / 3 source links

  • 3rd 23:28:42

    Earth Forms

    approximate date

    Earth enters the story after most of the cosmic year has already passed.

    • NASA Science

      Solar System facts

      This NASA page supports the timing for Solar System formation.

      Supports: about 4.6 billion years ago Calendar: early September approximate date

      Open source

    • NASA Science

      Facts About Earth

      This NASA page supports the timing for Earth's formation.

      Supports: Earth formed about 4.5 billion years ago Calendar: September 3rd, about 23:29 approximate date

      Open source

  • 17th 04:52:10

    Life Signals

    approximate date

    Possible early life appears as tiny, indirect evidence, long before animals or plants.

    • NASA Astrobiology

      How did life first emerge on Earth?

      This NASA page supports the timing for possible early life on Earth.

      Supports: life may have been on Earth about 4 billion years ago Calendar: September 17th, about 04:52 approximate date

      Open source

Calendar month

December

3 facts / 8 source links

  • 25th 22:00:00

    Dinosaurs

    approximate date

    Dinosaurs feel ancient, but the calendar shows they still arrive late in December.

    • Natural History Museum

      Where did dinosaurs come from?

      This source helps place the first dinosaur evidence late in December.

      Supports: around 230 million years ago Calendar: December 25th, about 22:00 approximate date

      Open source

  • 30th 06:06:00

    Dinosaur Extinction

    approximate date

    The dinosaur extinction marks a major turning point near the end of the cosmic year.

    • Natural History Museum

      Dinosaur extinction

      This source supports the extinction event near the end of December.

      Supports: about 66 million years ago Calendar: December 30th, about 06:06 approximate date

      Open source

  • 31st 23:48:34

    Humans Arrive

    approximate date

    Humans arrive only minutes before midnight, making our story feel very recent on this scale.

    • Smithsonian Human Origins Program

      Introduction to Human Evolution

      This source supports the broader time spread for early human evolution.

      Supports: human evolution over about 6 million years Calendar: December 31st, about 20:11 onward approximate date

      Open source

    • Penn State

      Earliest known fossil of the genus Homo

      This source supports the early Homo genus timing used in the human family spread.

      Supports: about 2.8-2.75 million years ago Calendar: December 31st, about 22:13-22:15 approximate date

      Open source

    • Smithsonian Human Origins Program

      Homo habilis

      This source supports one early named Homo species in the human family spread.

      Supports: about 2.4-1.65 million years ago Calendar: December 31st, about 22:29-22:57 approximate date

      Open source

    • Smithsonian Human Origins Program

      Homo erectus

      This source supports the Homo erectus timing in the human family spread.

      Supports: about 1.9 million to 143,000 years ago Calendar: December 31st, about 22:48-23:54 approximate date

      Open source

    • Smithsonian Human Origins Program

      Homo neanderthalensis

      This source supports the Neanderthal timing and relationship to the Homo genus.

      Supports: about 400,000-40,000 years ago Calendar: December 31st, about 23:45-23:58 approximate date

      Open source

    • Smithsonian Human Origins Program

      Homo sapiens

      This source helps place humans close to midnight on December 31.

      Supports: about 300,000 years ago Calendar: December 31st, 23:48:34 approximate date

      Open source

Image credit: NASA/JPL-Caltech. Background source: Age-Defying Star.