Doomsday Algorithm
Train Conway's Doomsday algorithm to mentally calculate the day of the week for any date
Each century has an anchor day that repeats in a cycle of 4. Memorize: Tuesday, Sunday, Friday, Wednesday (2000s, 2100s, 2200s, 2300s).
| Century | Anchor |
|---|---|
| 2000-2099 | Tue (2) |
| 2100-2199 | Sun (0) |
| 2200-2299 | Fri (5) |
| 2300-2399 | Wed (3) |
→ Tue (2)