| Big bang |
January 1 |
13.7 billion years ago |
| Stars and galaxies begin to form |
End of January/mid-February |
12 billion years ago |
| Milky Way galaxy forms |
March/early April |
10 billion years ago |
| Origin of the solar system |
September 9 |
4.7 billion years ago |
| Formation of the earth |
September 15 |
4.5 billion years ago |
| Earliest life on earth |
Late September/early October |
4 billion years ago |
| Oxygen forms on earth |
December 1 |
1.3 billion years ago |
| First worms |
December 16 |
658 million years ago |
| First fish, first vertebrates |
December 19 |
534 million years ago |
| First reptiles, first trees |
December 23 |
370 million years ago |
| Age of dinosaurs |
December 24–28 |
329–164 million years ago |
| First human-like creatures |
December 31 (late evening) |
2.7 million years ago |
| First agriculture |
December 31: 11:59:35 |
12,000 years ago |
| Birth of the Buddha/Greek civilization |
December 31: 11:59:55 |
2,500 years ago |
| Birth of Jesus |
December 31: 11:59:56 |
2,000 years ago |
| Aztec and Inca empires |
December 31: 11:59:59 |
500 years ago |