1840

Millennium: 2nd millennium
Centuries:
Decades:
Years:
1840 in various calendars
Gregorian calendar1840
MDCCCXL
Ab urbe condita2593
Armenian calendar1289
ԹՎ ՌՄՁԹ
Assyrian calendar6590
Balinese saka calendar1761–1762
Bengali calendar1247
Berber calendar2790
British Regnal yearVict. 1 – 4 Vict. 1
Buddhist calendar2384
Burmese calendar1202
Byzantine calendar7348–7349
Chinese calendar己亥年 (Earth Pig)
4537 or 4330
    — to —
庚子年 (Metal Rat)
4538 or 4331
Coptic calendar1556–1557
Discordian calendar3006
Ethiopian calendar1832–1833
Hebrew calendar5600–5601
Hindu calendars
 - Vikram Samvat1896–1897
 - Shaka Samvat1761–1762
 - Kali Yuga4940–4941
Holocene calendar11840
Igbo calendar840–841
Iranian calendar1218–1219
Islamic calendar1255–1256
Japanese calendarTenpō 11
(天保11年)
Javanese calendar1767–1768
Julian calendarGregorian minus 12 days
Korean calendar4173
Minguo calendar72 before ROC
民前72年
Nanakshahi calendar372
Thai solar calendar2382–2383
Tibetan calendar阴土猪年
(female Earth-Pig)
1966 or 1585 or 813
    — to —
阳金鼠年
(male Iron-Rat)
1967 or 1586 or 814
January 13: Steamship Lexington sinks.

1840 (MDCCCXL) was a leap year starting on Wednesday of the Gregorian calendar and a leap year starting on Monday of the Julian calendar, the 1840th year of the Common Era (CE) and Anno Domini (AD) designations, the 840th year of the 2nd millennium, the 40th year of the 19th century, and the 1st year of the 1840s decade. As of the start of 1840, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.