| Millennium: | 2nd millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 1646 by topic |
|---|
| Arts and science |
| Leaders |
| Birth and death categories |
| Births – Deaths |
| Establishments and disestablishments categories |
| Establishments – Disestablishments |
| Works category |
| Gregorian calendar | 1646 MDCXLVI |
| Ab urbe condita | 2399 |
| Armenian calendar | 1095 ԹՎ ՌՂԵ |
| Assyrian calendar | 6396 |
| Balinese saka calendar | 1567–1568 |
| Bengali calendar | 1053 |
| Berber calendar | 2596 |
| English Regnal year | 21 Cha. 1 – 22 Cha. 1 |
| Buddhist calendar | 2190 |
| Burmese calendar | 1008 |
| Byzantine calendar | 7154–7155 |
| Chinese calendar | 乙酉年 (Wood Rooster) 4343 or 4136 — to — 丙戌年 (Fire Dog) 4344 or 4137 |
| Coptic calendar | 1362–1363 |
| Discordian calendar | 2812 |
| Ethiopian calendar | 1638–1639 |
| Hebrew calendar | 5406–5407 |
| Hindu calendars | |
| - Vikram Samvat | 1702–1703 |
| - Shaka Samvat | 1567–1568 |
| - Kali Yuga | 4746–4747 |
| Holocene calendar | 11646 |
| Igbo calendar | 646–647 |
| Iranian calendar | 1024–1025 |
| Islamic calendar | 1055–1056 |
| Japanese calendar | Shōhō 3 (正保３年) |
| Javanese calendar | 1567–1568 |
| Julian calendar | Gregorian minus 10 days |
| Korean calendar | 3979 |
| Minguo calendar | 266 before ROC 民前266年 |
| Nanakshahi calendar | 178 |
| Thai solar calendar | 2188–2189 |
| Tibetan calendar | 阴木鸡年 (female Wood-Rooster) 1772 or 1391 or 619 — to — 阳火狗年 (male Fire-Dog) 1773 or 1392 or 620 |
1646 (MDCXLVI) was a common year starting on Monday of the Gregorian calendar and a common year starting on Thursday of the Julian calendar, the 1646th year of the Common Era (CE) and Anno Domini (AD) designations, the 646th year of the 2nd millennium, the 46th year of the 17th century, and the 7th year of the 1640s decade. As of the start of 1646, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.
It is one of eight years (CE) to contain each Roman numeral once (1000(M)+500(D)+100(C)+(-10(X)+50(L))+5(V)+1(I) = 1646).