- 0 ... 12-hydroxyloleic acid
- 12-step program ... 1857, Panic of
- 1860, Movement of ... 1O1
- 1Q84 ... 2021 Israel-Palestine crisis
- 2021 Myanmar coup d’état ... 33rd Day of the ʿOmer Counting
- 33rd U.S. Colored Troops ... 51 Pegasi b
- 52 Pick-Up ... 9,10-anthraquinone
- 9-1-1 ... 9to5, National Association of Working Women