Monday is the first day of the work week or business week. The ISO 8601 which defines the numeric representations of date and time also specifies that Monday is the first day of the week. As per ISO 8601 Monday is day1 and Sunday is day7.
Monday is preceded by Sunday and followed by Tuesday. In several religions Monday is the second day of the week and Sunday is the first day of the week.
Monday is named after the Moon.In old English mondæg literally means "day of the moon".
Monday is also the first trading day for most of the stock markets in the world. When there is a huge loss in financial markets on a monday, people term it is as a black monday. This is mainly because during Saturday and Sunday, the markets are closed and any big news that happen over weekend affect the markets on Monday.
The Uniform Monday Holiday Act in the USA has made that important holidays to be observed on Monday.