Monday gets its name from the Anglo-Saxon word "mondandaeg" which translates to "the moon's day. The second day of the week in Nordic cultures was devoted to worshipping the goddess of the moon."
The legal working week (British English), or workweek (American English), is the part of the seven-day week devoted to labour. In most of the Western world, it is Monday to Friday; the weekend is Saturday and Sunday. In some Christian traditions, Sunday is the "day of rest and worship".
Traditionally, it is believed that a 5-day work week is more productive. A 6-day work week stresses people out and doesn't give them enough time to spend with their families. The week seems too long and the weekend seems too short, and there is an imbalance with five days of stress and two days of recreation.