| Millennium: | 1st millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| Gregorian calendar | 842 DCCCXLII |
| Ab urbe condita | 1595 |
| Armenian calendar | 291 ԹՎ ՄՂԱ |
| Assyrian calendar | 5592 |
| Bengali calendar | 249 |
| Berber calendar | 1792 |
| Buddhist calendar | 1386 |
| Burmese calendar | 204 |
| Byzantine calendar | 6350–6351 |
| Chinese calendar |
辛酉年 (Metal Rooster) 3538 or 3478 — to — 壬戌年 (Water Dog) 3539 or 3479 |
| Coptic calendar | 558–559 |
| Discordian calendar | 2008 |
| Ethiopian calendar | 834–835 |
| Hebrew calendar | 4602–4603 |
| Hindu calendars | |
| - Vikram Samvat | 898–899 |
| - Shaka Samvat | 763–764 |
| - Kali Yuga | 3942–3943 |
| Holocene calendar | 10842 |
| Iranian calendar | 220–221 |
| Islamic calendar | 227–228 |
| Japanese calendar |
Jōwa 9 (承和9年) |
| Javanese calendar | 739–740 |
| Julian calendar | 842 DCCCXLII |
| Korean calendar | 3175 |
| Minguo calendar | 1070 before ROC 民前1070年 |
| Nanakshahi calendar | −626 |
| Seleucid era | 1153/1154 AG |
| Thai solar calendar | 1384–1385 |
Year 842 (DCCCXLII) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar.