| Big Bang | January 1 |
| Origin of Milky Way Galaxy | May 1 |
| Origin of the solar system | September 9 |
| Formation of the Earth | September 14 |
| Origin of life on Earth | ~ September 25 |
| Formation of the oldest rocks known on Earth | October 2 |
| Date of oldest fossils (bacteria and blue-green algae) | October 9 |
| Invention of sex (by microorganisms) | ~ November 1 |
| Oldest fossil photosynthetic plants | November 12 |
| Eukaryotes (first cells with nuclei) flourish | November 15 |
| Sunday | Monday | Tuesday | Wednesday | Thursday | Friday | Saturday |
|---|---|---|---|---|---|---|
| 1 Significant oxygen atmosphere begins to develop on Earth. |
2 | 3 | 4 | 5 Extensive vulcanism and channel formation on Mars. |
6 | |
| 7
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8 | 9 | 10 | 11 | 12 | 13 |
| 14
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15 | 16 First Worms. |
17 Precambrian ends. Paleozoic Era and Cambrian Period begin. Invertebrates flourish. |
18 First oceanic plankton. Trilobites flourish. |
19 Ordovician Period. First fish, first vertebrates. |
20 Silurian Period. First vascular plants. Plants begin colonization of land. |
| 21 Devonian Period begins. First insects. Animals begin colonization of land.
|
22 First amphibians. First winged insects. |
23 Carboniferous Period. First trees. First reptiles. |
24 Permian Period begins. First dinosaurs. |
25 Paleozoic Era ends. Mesozoic Era Begins. |
26 Triassic Period. First mammals. |
27 Jurassic Period. First birds. |
| 28 Cretaceous Period. First flowers. Dinosaurs become extinct.
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29 Mesozoic Era ends. Cenozoic Era and Tertiary Period begin. First cetaceans. First primates. |
30 First evolution of frontal lobes in the brains of primates. First hominids. Giant mammals flourish. |
31 End of Pliocene Period. Quaternary (Pleistocene and Holocene) Period. First humans. |
| Origin of Proconsul and Ramapithecus, probable ancestors of apes and men | ~ 1:30 p.m. |
| First humans | ~ 10:30 p.m. |
| Widespread use of stone tools | 11:00 p.m. |
| Domestication of fire by Peking man | 11:46 p.m. |
| Beginning of most recent glacial period | 11:56 p.m. |
| Seafarers settle Australia | 11:58 p.m. |
| Extensive cave painting in Europe | 11:59 p.m. |
| Invention of agriculture | 11:59:20 p.m. |
| Neolithic civilization; first cities | 11:59:35 p.m. |
| First dynasties in Sumer, Ebla and Egypt; development of astronomy | 11:59:50 p.m. |
| Invention of the alphabet; Akkadian Empire | 11:59:51 p.m. |
| Hammurabic legal codes in Babylon; Middle Kingdom in Egypt | 11:59:52 p.m. |
| Bronze metallurgy; Mycenaean culture; Trojan War; Olmec culture; invention of the compass | 11:59:53 p.m. |
| Iron metallurgy; First Assyrian Empire; Kingdom of Israel; founding of Carthage by Phoenicia | 11:59:54 p.m. |
| Asokan India; Ch'in Dynasty China; Periclean Athens; birth of Buddha | 11:59:55 p.m. |
| Euclidean geometry; Archimedean physics; Ptolemaic astronomy; Roman Empire; birth of Christ | 11:59:56 p.m. |
| Zero and decimals invented in Indian arithmetic; Rome falls; Moslem conquests | 11:59:57 p.m. |
| Mayan civilization; Sung Dynasty China; Byzantine empire; Mongol invasion; Crusades | 11:59:58 p.m. |
| Renaissance in Europe; voyages of discovery from Europe and from Ming Dynasty China; emergence of the experimental method in science | 11:59:59 p.m. |
| Widespread development of science and technology; emergence of global culture; acquisition of the means of self-destruction of the human species; first steps in spacecraft planetary exploration and the search of extraterrestrial intelligence | Now: The first second of New Year's Day |