Do you know the reason why a week has 7 days and not less / more?
Also, do you know where the week day names actually derive from?
I like to suggest a new tag called To the point (ttp) where information are concentrated in easy to read and digest bullet points, rather than watered down in hundred lines of text.
Origin of the 7 day week
IMG source timeanddate.com
The origin of a 7 day week is based on Babylonian observations of the Moon cycles around 500 BC (Before Christ).
The Babylonian's observed that it takes the Moon 29 days to cycle through all Moon phases.
Since a single 29 day cycle would be too long and impractical, the Babylonians broke it down into 4 parts, based on the 4 phases of the moon.
- New moon
- First quarter
- Full moon
- Last quarter
Initially there where three times 7 days and one time 8 days. Starting with the introduction of the Julian Calendar around 46 BC the 8 day week disappeared and changed to 4 times 7 days.
Summary The reason we have a 7 day week derives from 1/4 of the time needed for the moon to cycle through all 29 Moon phases (1 lunar month).
Origin of the week day names
IMG source timeanddate.com
- The Babylonians developed 500 BC a horoscope where each day of the week was assigned to one of the 7 classical planets visible to the naked eye and ordered by the speed they crossed the sky.(The earth was considered the center back then).
- Moon
- Mercury
- Venus
- Sun
- Mars
- Jupiter
- Saturn
- The day names we know and use today however origin from the Romans and Saxon's. They also used the 7 planets as their baseline but assigned one of their pagan gods to each of them.
| Classical Planet | Roman Gods (Latin) | Anglo-Saxon Gods | English |
|---|---|---|---|
| Moon | Luna | Moon | Monday |
| Mercury | Mercurii | Woden (Odin) | Wednesday |
| Venus | Veneris | Frigg | Friday |
| Sun | Solis | Sun | Sunday |
| Mars | Martis | Tiw | Tuesday |
| Jupiter | Jovis | Thor | Thursday |
| Saturn | Saturni | Saterne | Saturday |
- The sorting of the week days as we know it today is a result of the Planetary hours. (e.g. day with its first hour ruled by the Sun ("Sunday") is followed by a day with its first hour ruled by the Moon ("Monday"), followed by Mars ("Tuesday")