History from the side of those it happened to
On this day — December 21
| Date | Country | Category | Title |
|---|---|---|---|
| 21 December 2012 | Mexico | Mathematics | Publication explains the Maya calendar and zero |
| 21 December 2012 | Mexico | Mathematics | The Maya combine cycles of different lengths |
| 21 December 2012 | Mexico | Mathematics | Maya numerals use a vigesimal place-value system |
| 21 December 2012 | Mexico | Mathematics | The article counters apocalyptic misreadings |