Cosmic Calendar

The Cosmic Calendar is a scale in which the lifetime of the universe is mapped onto a calendrical year; that is to say, the Big Bang took place on a cosmic January 1 at precisely midnight, and today's date and time is December 31 at midnight.^[1] On this calendar, the solar system did not appear until September 9, life on Earth arose on September 30, the first dinosaurs appeared on December 25th, the first flowers on December 28th, and the first primates on December 30. The first humans did not arrive until around 10:30 p.m. on New Year's Eve, and all of human history has been recorded in the last minute. The Middle Ages to the present is a little more than one second. On this timescale, an average human life is about 0.15 seconds. The scale was popularized by Carl Sagan in his book The Dragons of Eden and on the television series Cosmos, which he hosted.

January, 1 - Big Bang
May, 1 - Milky Way Galaxy formed
September, 9 - Solar System formed
September, 14 - Earth formed
September, 25 - Oldest rocks known on Earth

October, 2 - Life on Earth
October, 9 - Oldest fossils
November,1 - Development of sex
November, 12 - Oldest fossil of photosynthetic plants
November, 15 - Eukaryotes flourish
December, 1 - Oxygen atmosphere begins to develop
December, 17 - Invertebrates flourish
December, 18 - First oceanic plankton
December, 19 - Fish and Vertebrates appear
December, 20 - Vascular plants appear. Plants begin colonization of land
December, 21 - Insects appear, animals begin colonization of land

December, 22 - Amphibians and Winged insects appear
December, 23 - Trees and Reptiles appear
December, 24 - Dinosaurs appear and dominate for over 160 million years
December, 26 - First mammals
December, 27 - First birds, first Flowers

December, 28 - K-T mass extinction, many forms of life perished, including dinosaurs

December, 29 - First primates
December, 30 - Early brain evolution of primates, first hominids
December, 31 Time 13.30.00 - Ancestors of apes and men
December, 31 Time 22.30.00 - First humans
December, 31 Time 23.00.00 - Use of stone tools
December, 31 Time 23.46.00 - Domestication of fire
December, 31 Time 23.56.00 - Most recent glacial period
December, 31 Time 23.59.00 - Rupestral painting in Europe
December, 31 Time 23.59.20 - Agriculture
December, 31 Time 23.59.35 - Neolithic civilization

December, 31 Time 23.59.50: End of prehistory and beginning of history, Dynasties in Sumer, Ebla and Egypt, Astronomy
December, 31 Time 23.59.51: Alphabet, Akkadian Empire Wheel is invented
December, 31 Time 23.59.52: Hammurabic legal codes in Babylon, Middle Kingdom in Egypt
December, 31 Time 23.59.53: Bronze metallurgy, Mycenaean culture, Trojan War, Olmec culture
December, 31 Time 23.59.54: Iron metallurgy, Assyrian Empire, Kingdom of Israel, Founding of Carthage

December, 31 Time 23.59.55: Birth of Buddha and Confucius, Ch'in Dynasty China, Periclean Athens, Asokan Indian empire, Indian Veda holy scriptures are completed
December, 31 Time 23.59.56: Euclidean geometry, Archimedean physics, Ptolemaic astronomy, Greek Olympic games, Roman Empire, Birth of Christ
December, 31 Time 23.59.57: Birth of Muhammad, Zero and decimals invented in Indian arithmetic, Rome falls, Moslem conquests
December, 31 Time 23.59.58: Mayan civilization, Sung Dynasty China, Byzantine empire, Mongol invasion, Crusades.

December, 31 Time 23.59.59: Voyages of discovery from Europe and from Ming Dynasty China, Columbus lands in America, Renaissance in Europe

December, 31 Time 24.00.00: Beginning of modern culture, science and technology development, French revolution, World War I, World War II, Apollo lands on the moon, Spacecraft planetary exploration, Search for extraterrestrial intelligence.