The Days of the Week in the West

Before looking at Chinese, Japanese, Vietnamese, and Mongolian names, let's take a brief look at the origins of the week in the West. (This is a very brief summary. The development of the week from its ancient origins is both complex and fascinating. To get a full picture, you need to look at some of the many other sites around.)

Planetary names

The seven-day week is believed to have originated with the ancient Babylonians. The Babylonians arrived at the 'week' by dividing the lunar month into four lots of seven days each.

It is possible that the Babylonians named each day after the 'seven planets', i.e., the sun, the moon, and the five planets visible to the naked eye, with each planet being named after a Babylonian god. Others attribute the planetary names to the Egyptians, and yet others to the Greeks. The view that the custom was begun by the Greeks appears to be most widely accepted.

In the ancient Greek naming, apart from the sun and the moon, the five planets were named after Ares, Hermes, Zeus, Aphrodite, and Chronos. The ancient Greek names were:

In about the 1st century BC, the Romans also started using the seven-day week, replacing their earlier eight-day system. Like the Greeks before them, they named the five planets after their own gods: Mars, Mercury, Jove (Jupiter), Venus, and Saturn. The days of the week in Latin became:

The Germanic peoples continued the tradition by substituting their own gods for the Roman ones according to the conventions of the time, namely Tiu (Tiw), Woden, Thor, and Freyja. Only Saturn was retained from the Roman pantheon.

One big difference here, however, is that the Germanic languages do not (or no longer) name the planets after their gods, and the link with the planets has effectively been broken. The English words Tuesday, Wednesday, Thursday, and Friday, descended from the Germanic names, are now purely names of gods and have lost any relationship with the planets Mars, Mercury, Jupiter, and Venus.

Hebrew and Christian names

The other source of day names in some Western European languages (but not English) was the Jewish and Christian calendars. Like many ancient peoples, the Hebrews used a seven-day week, which they possibly got from the Babylonians. The Hebrews did not use planetary names, preferring to designate the days by number. Only the seventh was given a specific name, that of the 'Sabbath'. The Jewish Sabbath, which corresponded to Saturday, was the day of rest and the last day of the week.

Christianity inherited this Jewish conception of the week. However, while the Sabbath was retained in theory, Christians gradually came to put more emphasis on the day after the Sabbath, which was identified as the 'Lord's Day' in celebration of Christ's resurrection at Easter. Sunday, the first day of the week, became both a day of worship and a day of rest for Christians.

The Christian version of the week was officially adopted by the Roman Emperor Constantine in AD 321. The old Sunday (dies solis) was specified as the 'Lord's Day' (dies Domenica) and identified as the first day of the week (Note: Is Monday the first day?). The rest of the week was numbered in accordance with this.

The modern Greek names for the days of the reflect this conception of the week:

Modern Western names

In the West, despite attempts by Pope Silvester (who served from 314 to 335) to impose a system of numbering, the old pagan names persisted. They still form the basis of the modern names in Western European languages, which feature a mixture of Christian and pagan elements.

English and other Germanic languages largely retain the sun, the moon, and the names of the Germanic gods.

Italian, French, and Spanish adopt Judaeo-Christian religious terminology for Saturday (the Sabbath) and Sunday (the Lord's Day), but retain the Roman planetary names for the days of the week.

Only Portuguese has done away with the planetary names by substituting numbered days for the weekdays.

The above is a highly simplified treatment of the origins of the names of the days of the week. For a more complete coverage of this fascinating subject, please refer to the Web Links. Be warned, however, that there is no unanimity of views!

For reference, the days of the week in several Western European languages are given below:

Notes: German 'Mittwoch' means 'mid-week'. Swedish 'lördag' means 'bathing day'.

Outside the West, the naming of the days of the week exhibits considerable variety, with different traditions found in Slavic languages, Hebrew, Arabic, and Persian.

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