Monday: the Moon’s Day

Monday is the first day of the week according to the international standard ISO 8601, but in the US, Canada, and Japan, it's counted as the second day of the week.

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Monday is named after the Moon.


Monday comes after Sunday and before Tuesday in our modern-day Gregorian Calendar.

Naming Monday

The English word Monday is derived from Old English and means “the Moon's day.”

  • Middle English – Monday or mone(n)day
  • Latin – dies lunae – Day of the Moon
  • Old Norse – mánadagr, mandag, mánudagur
  • Old English – mōnandæg or mōndæg
  • Ancient Greek – hemera selenes – Day of the Moon

First or Second Day?

According to the international standard ISO 8601, Monday is considered the first day of the week. Most European countries' calendars show Monday as the first day of the week. However, in many cultures and languages, Monday is given a name that means either “second day,” marking Sunday to be the first day of the week, or a name that means the day after Sunday.

Holidays on a Monday

Several US holidays, such as Labor Day, Memorial Day, and Columbus Day always fall on a Monday. In the UK, there are three bank holidays on Mondays plus Easter Monday, which is also a day off.

Depressing “Blue” Monday

Monday used to be called “Blue Monday” because it was a day associated with washing clothes that involved blue dye. However, it now refers to the day employees reluctantly return to work after the weekend.

“I Don't Like Mondays”

In many cultures, Monday is considered the worst day of the week because it is the first day of the workweek. Song lyrics often feature Monday as a day of depression, anxiety, or melancholy such as “Monday, Monday” by the Mamas & the Papas in 1966 or “Rainy Days and Mondays” by the Carpenters in 1971, not to mention “I Don't Like Mondays” by the Boomtown Rats in 1979.

However, Mondays are considered good days for fasting in Judaism and Islam. In the Eastern Orthodox Church, Angels are commemorated on Mondays.

Topics: Weekdays