This airticle is aboot the year 1640.

1640 (MDCXL) wis a leap year stairtin on Sunday o the Gregorian calendar and a leap year stairtin on Wadensday o the Julian calendar, the 1640t year o the Common Era (CE) an Anno Domini (AD) designations, the 640t year o the 2nt millennium, the 40t year o the 17t century, an the 1st year o the 1640s decade. As o the stairt o 1640, the Gregorian calendar wis 10 days aheid o the Julian calendar, that remeened in localised use till 1923.

Millennium: 2nt millennium
Centuries: 16t century17t century18t century
Decades: 1610s  1620s  1630s  – 1640s –  1650s  1660s  1670s
Years: 1637 1638 163916401641 1642 1643