| Millennium: | 1st Millennium |
|---|---|
| Centuries: | 2nd cent. – 3rd cent. – 4th cent. |
| Decades: | 210s 220s 230s – 240s – 250s 260s 270s |
| Years: | 239 240 241 – 242 – 243 244 245 |
| Gregorian calendar | 242 CCXLII |
| Ab urbe condita | 995 |
| Assyrian calendar | 4992 |
| Bengali calendar | −351 |
| Berber calendar | 1192 |
| Buddhist calendar | 786 |
| Burmese calendar | −396 |
| Byzantine calendar | 5750–5751 |
| Chinese calendar | 辛酉年 (Metal Rooster) 2938 or 2878 — to — 壬戌年 (Water Dog) 2939 or 2879 |
| Coptic calendar | −42 – −41 |
| Discordian calendar | 1408 |
| Ethiopian calendar | 234–235 |
| Hebrew calendar | 4002–4003 |
| Hindu calendars | |
| - Vikram Samvat | 298–299 |
| - Shaka Samvat | 163–164 |
| - Kali Yuga | 3342–3343 |
| Holocene calendar | 10242 |
| Iranian calendar | 380 BP – 379 BP |
| Islamic calendar | 392 BH – 391 BH |
| Javanese calendar | 120–121 |
| Julian calendar | 242 CCXLII |
| Korean calendar | 2575 |
| Minguo calendar | 1670 before ROC 民前1670年 |
| Nanakshahi calendar | −1226 |
| Seleucid era | 553/554 AG |
| Thai solar calendar | 784–785 |
The year 242 BC