| 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 |