Cosmic Calendar


The Cosmic Calendar is a method to visualize the chronology of the universe, scaling its current age of 13.8 billion years to a single year in order to help intuit it for pedagogical purposes in science education or popular science.
In this visualization, the Big Bang took place at the beginning of January 1 at midnight, and the current moment maps onto the end of December 31 just before midnight.
At this scale, there are 437.5 years per second, 1.575 million years per hour, and 37.8 million years per day.
The concept was popularized by Carl Sagan in his book The Dragons of Eden and on his television series . Sagan goes on to extend the comparison in terms of surface area, explaining that if the Cosmic Calendar is scaled to the size of a football field, then "all of human history would occupy an area the size of hand".

The Cosmic Year

The Cosmic Calendar shows the time-scale relationship of the universe and all events on Earth as plotted along a single 12-month, 365-day, year. On this scale, one second corresponds to 438 years; a minute is about 26,000 years; an hour is 1.6 million years; and a day is 38 million years.

Cosmology

Date in year calculated from formula
T = 365 days * 0.100/13.797

Evolution of life on Earth

DateBya Event
14 Sep4.1First known remains of biotic life.
21 Sep3.8First Life
30 Sep3.4Photosynthesis
29 Oct2.4Oxygenation of Atmosphere
9 Nov2Complex Cells
5 Dec0.8First Multicellular Life
7 Dec0.67Simple Animals
14 Dec0.55Arthropods
17 Dec0.5Fish and Proto-amphibians
20 Dec0.45Land Plants; Ordovician–Silurian extinction events
21 Dec0.4Insects and Seeds
22 Dec0.36Amphibians; Late Devonian extinction
23 Dec0.3Reptiles
24 Dec0.25Permian–Triassic extinction event; 57% of all biological families and 83% of all genera die
25 Dec0.23Dinosaurs
26 Dec0.2Mammals; Triassic–Jurassic extinction event
27 Dec0.15Birds
28 Dec0.13Flowers
30 Dec, 06:240.065Cretaceous–Paleogene extinction event, non-avian dinosaurs die out

Human evolution

Date / timemyaEvent
30 Dec65Primates
31 Dec, 06:0515Apes
31 Dec, 14:2412.3Hominids
31 Dec, 22:242.5Primitive Humans and Stone Tools
31 Dec, 23:440.4Domestication of Fire
31 Dec, 23:520.2Anatomically Modern Humans
31 Dec, 23:550.11Beginning of Most Recent Glacial Period
31 Dec, 23:580.035Sculpture and Painting
31 Dec, 23:59:320.012Agriculture

History begins

Date / timekyaEvent
31 Dec, 23:59:3312.0End of the Ice Age
31 Dec, 23:59:418.3Flooding of Doggerland
31 Dec, 23:59:466.0Chalcolithic
31 Dec, 23:59:475.5Early Bronze Age; Proto-writing; Building of Stonehenge Cursus
31 Dec, 23:59:485.0First Dynasty of Egypt, Early Dynastic Period in Sumer, Beginning of Indus Valley Civilisation
31 Dec, 23:59:494.5Alphabet, Akkadian Empire, Wheel
31 Dec, 23:59:514.0Code of Hammurabi, Middle Kingdom of Egypt
31 Dec, 23:59:523.5Late Bronze Age to Early Iron Age; Minoan eruption
31 Dec, 23:59:533.0Iron Age; Beginning of Classical Antiquity
31 Dec, 23:59:542.5Buddha, Mahavira, Zoroaster, Confucius, Qin Dynasty, Classical Greece, Ashokan Empire, Vedas Completed, Euclidean geometry, Archimedean Physics, Roman Republic
31 Dec, 23:59:552.0Ptolemaic astronomy, Roman Empire, Christ, Invention of Numeral 0, Gupta Empire
31 Dec, 23:59:561.5Muhammad, Maya civilization, Song Dynasty, Rise of Byzantine Empire
31 Dec, 23:59:581.0Mongol Empire, Maratha Empire, Crusades, Christopher Columbus Voyages to the Americas, Renaissance in Europe, Classical Music to the Time of Johann Sebastian Bach

The current second

Future

Future of the Earth and Solar System ("Year 2")

Future of the Universe ("Year 3" and beyond)