An ancient Egyptian ten day calendar carved into stone

Anthropology: How Babylonian Astronomy, Roman Deities, and Pagan Gods Inspired the Modern Seven-Day Week

The Seven-Day Week Dominates

Credit: Old Farmer’s Almanac

Modern Meaning of Days

Calendars seem to run human existence. Our entire lives whirl around the various days of the week. Even our habits sync to the different days. Monday typically means a new workweek. It represents new beginnings and a fresh start. Tuesday, Wednesday, and Thursday mesh together in a sort-of midweek hurdle. Friday as the holy-grail of weekdays. It’s the day for happy-hour after work, a time to unwind. Saturday is renowned as a day spent with family. It’s an opportunity to rest and recharge. This leaves Sunday as the limbo between weekend fun and weekday duties. One might even contract a case of the “Sunday Blues” or “Sunday Scaries.” We associate these feelings with the dread of starting a new week. A new week means resuming work or responsibilities.

Astronomical Influences

This seven-day week is accepted without a second thought. Where exactly did the concept of a seven-day week come from, though? Who initially labeled each day in cyclic fashion? Where did the names originate? The answer isn’t simple. It’s a bit more complex than one might assume. Astrological events and celestial bodies heavily inspired the numerical significance of the seven-day week. Congruently, ancient gods and deities inspired the naming of these days. Each day traditionally offers an opportunity for worship and thanksgiving. Let’s start by traveling back in time to early Mesopotamia. All the way back to the first millennium. The answer is, literally, written in the stars.

The Babylonian Creation of the Seven-Day Week

Stars in the night sky
Credit: Washington News

Babylonian Astronomy and the Concept of Time

In early Mesopotamia, the movement of the heavens—the stars, sun, moon, and planets—inspired the Babylonians. These celestial bodies seemed to synchronize with the daily habits of humans. Their lives seemed indirectly influenced by the movement overhead. These observations intrigued Babylonian astronomers. Early astronomers recognized the mathematical patterns of space. They even discovered how this movement correlates to the concept of time. For instance, they observed that one full rotation of Earth around its axis marks one full day. An entire revolution of the Earth around the sun—or 365 ¼ days—marks an entire year. They used these observations to implement a solar calendar. This calendar allows humanity to tell time. It also offers the opportunity to communicate this concept of time and coordinate on a grand scale.

The Mathematical Calculation of Days

The Babylonians were so meticulous that they even ensured the inclusion of leap year. This leap year, February’s additional day every four years makes up for the extra ¼ day each year. However, not every measure of time fits neatly into a coordinated package. For instance, the moon cycle is a little over 27 days long. It includes 13 phases throughout each solar year. This means the cycle doesn’t exactly correspond to a full calendar month. That’s why the concept of months and weeks was a little trickier to conceive than the easily understood solar-based days and years. The moon cycle—or lunar cycle—still heavily influences the calculation of months throughout the solar year. This cycle sets the standard for months, lasting about thirty days long on average.

Dividing the Lunar Cycle

The full 28-day moon cycle was still too long of a time period. The Babylonians thus divided it into four equal parts. This division of four seven-day weeks inspired better time management. Unlike the days and years that neatly follow solar patterns, the weeks and months did not. This resulted in some inevitable yet accepted inconsistencies. However, because of the popularity and dominance of Babylonian culture, other cultures maintained the seven-day calendar. Other Babylonian concepts of time, such as sixty minute hours, also prevailed.

Lunar cycle and the phases of the moon
Credit: Google Images

Why Seven-Day Weeks?

Where exactly did the Babylonians get the number seven from in these calculations? The seven-day week ultimately was adopted because of the Babylonians’ observations of the seven celestial bodies. The naked eye observed seven total celestial bodies at the time. They believed these celestial bodies to be gods. These “gods” inspired the names for the days of the week. The five recognized planets known to them at the time were Mercury, Venus, Mars, Jupiter, and Saturn. The sun and the moon were the final two inspirations. Since these were the seven significant celestial bodies seen with the naked eye, the number seven held great importance to them.

Babylonian Influence on Other Cultures and Seven-Day Weeks

An early Babylonian calendar artifact
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Egyptian Decans and the Extinct Ten-Day Week

Though the seven-day week is familiar to people

in modern times, this wasn’t the only option initially. For instance, early Egyptians divided their months into decans. These decans consist of three ten-day periods, rather than four seven-day periods. The Egyptians followed the solar calendar, similar to the Babylonians. However, their twelve months broke down a little differently. The Egyptians divided their 365-day year into three seasons of 120 days each. On top of these seasons was the inclusion of five extra days, to equal 365 total days. Despite this, their calendar did not quite match up with the solar year. They lost an entire day every four years. This was something the Babylonians did not, likely thanks to their leap year.

Egyptians and Lunar Influences

It’s thought that the Egyptians based their initial calendars on lunar cycles, rather than solar cycles. Their calendar accounted primarily for the moon’s phases throughout the month. Since lunar cycles run closer to ten-day periods than seven days, it’s likely why ten stuck out to them. Though the Egyptians were not the only culture to adapt a week consisting of another number than seven, they were one of the most popular oppositions. Though the Babylonian week won the battle, sticking around for the long-term with its seven-day week. It goes to show just how influential the Babylonian culture was in the early millennium.

An ancient Egyptian ten day calendar carved into stone

The Romans and an Eight-Day Week

Originally, the Romans followed an eight-day week. They even used a system of dominical letters (A-G) to determine the days of the week, rather than identifying the days with proper names. The Romans devoted the first seven days of the week to working. On that eighth and final day, they would shop and prepare for the new week. However, when they began conquering Alexander the Great’s territory, influence shifted. The seven-day week began rising in popularity. In early 321 A.D., Emperor Constantine declared seven-day weeks the standard. This standard included Sunday as a holiday—the day of shopping.

Roman Deities and the Switch to Seven-Day Weeks

Even as Christianity became the leading religion of the Romans, they continued to adhere to the seven-day week. The major change was the value of Saturday, rather than Sunday. Christians adopted the ancient Israelites’ seventh day of rest. This was the only named day of the week for Israelites at the time—Sabbath. Shopping and preparing for the week on Sunday was no longer the standard. Instead, Saturday became a day of rest, carried over from the Jewish Sabbath. This transferred to Christianity, and thus to the Roman Empire wholly. Sabbath counted as the seventh, and final, day of the week. This likely contributes to Sunday as the start of a new week, or the first day of the week, rather than Monday.

Roman Days of the Week in Latin

The Romans initially based the names of the days of the week on their own deities. The Latin names for the days of the week are: dies Lunae (Luna’s Day) named after the moon goddess, Luna, for Monday; Tuesday is dies Martis (Mar’s Day) named after the god of war, Mars; Wednesday is dies Mercurii (Mercury’s Day) named after the god of commerce and messenger, Mercury; Thursday is dies Jovis (Jupiter’s Day) named after the god of sky and thunder, Jupiter; Friday is dies Veneris (Venus’s Day) in honor of the goddess of love, Venus; Saturday is dies Saturni (Saturn’s Day) after the planet; finally, Sunday is dies Solis (Sol’s Day) after the Roman sun god, Sol. Modern-day Spanish speakers might notice the similarities between these names compared to the original Roman names; this is because Latin heavily influenced the Spanish language. The days of the week in Modern Spanish are: lunes, martes, miércoles, jueves, viernes, sábado, and domingo.

Ancient Roman
Credit: The Fact Site

Anglo-Saxons and the Seven-Day Week

Eventually, Roman and Germanic people came into contact. Inspired by the success of the Roman empire, these Germanic tribes—Anglo-Saxons among them—followed the Roman seven-day calendar. However, they changed some of the names to worship their own gods instead of the Roman deities. These names were based on the original Pagan gods, with an Anglo-Saxon twist. These were the gods worshipped by many Anglo-Saxons and Norse people alike, before Christianity rose to popularity. The designated names of the week were Monandæg, Tiwesdæg, Wodnesdæg, Ðunresdæg, Frigedæg, Sæternesdæg, and Sunnandæg.

Anglo-Saxon Days of the Week in Old English

Though these words are Anglo-Saxon, also known as Old English in new times, it isn’t difficult to see how Modern English stayed close to the original names: Monandæg or Monday, is known literally as Moon’s day, or the day of the moon; Tiwesdæg, or Tuesday, is the day of the Scandinavian sky god. This god is known by a few names, such as Tiw,Tiu or Tig, resulting in the name of Tiw’s-day; Wodnesdæg, or Wednesday, is Woden’s day—the god of war, and an original god in Norse mythology;  Ðunresdæg, or Thursday, comes from Thor’s Day. This is the day of the god Ðunor or Thunor (Thor). Thor is the Norse god of thunder and lightning; Frigedæg is Freyja’s day—after the goddess of love, Freyja, who was wife to Woden—and translates to Friday; Sæternesdæg is Saturn’s day, or Saturday. The day of the Roman god Saturn, a god associated with wealth, plenty and time; finally, there is Sunnandæg, or Sunday. Quite literally translating from Sun’s day, or the day of the sun.

Anglo-Saxons prepare for battle

Norse Mythology and Original Pagan Gods

 Similarly to the Anglo-Saxons, the Nordics were Germanic folk who originally believed in Paganism. They worshipped the old Germanic gods. Though there are many similarities between the Norse and Anglo-Saxon cultures, the main difference is that Nordic people worshipped the original Pagan gods.  Meanwhile, the Anglo-Saxons adopted these gods as their own, prior to converting to Christianity.  For instance, the Anglo-Saxon worship the god Woden. Woden, known as the god of war, was originally Odin in Norse mythology. Though the changes are small, they’re still significant enough to result in different names for days of the week.

Old Norse Days of the Week

In Old Norse the days were: Mánadagr, named after the moon, which was known as “Mani” in Nordic areas; Tysdagr, named after Tyr who was the god of justice and war; Óðinsdagr, derived from the name of Odin, the most powerful and prominent god in Norse mythology; Þórsdagr, named after Thor, the god of thunder. Frjádagr, named after Frigg, the goddess of marriage and love, and the wife of Odin. Laugardagr, translated as ‘the day of bathing’ or ‘day of hot water’ since ‘laug’ means bath or hot water and ‘dagr’ means day; Sunnudagr, the day of ‘Sol’ or sun. Though the Norse and Anglo-Saxon names are quite similar, they still vary enough to highlight the linguistic, cultural, and religious differences between the two cultures.

Persisting Over Time, Despite Differing Cultural Influences

Norse mythology
Credit: The Gallerist

Recapping the Timeline

To recap the timeline, we return to early AD Babylonia. This is where astute astrologers observed changes in the night sky. They connected those changes with the solar-cycle and human concepts of time. These Babylonians then implemented a seven-day week based on their observations and interpretations of celestial bodies as deities. Because of its cultural prominence, this Babylonian influence stuck around, subsequently shaping the Roman and Germanic calendars.

The Roman, Nordic, and Anglo-Saxon people each adopted this feature, while adding their own deities for worship in their own languages. Though times have changed, these original names are still apparent in the modern languages. For instance, the Latin-based Roman names for the days of the week shine through the Modern Spanish names. Anglo-Saxon and Old Norse names are apparent in Modern English (which is heavily based on Old English and other Old Germanic languages).


Pinpointing Cultural Significances in Anthropology

Despite the differences in these cultures and timeframes, the names of the days of the week reflect the influence of early religion and astrology. One thing the Babylonians, Romans, and Anglo-Saxons had in common is their fascination with celestial bodies and the worship of gods. They associated each day of the week with a planet, gods, or both. This offered a specific day of designated worship and thanksgiving. Modern English names for days of the week are based on the Babylonian’s original seven-day calendar—and subsequent Roman adaptation—but also heavily inspired by the Anglo-Saxons and their old Germanic and Norse gods.

Contemporary times have changed. The worship of gods and planetary fascination is not as prevalent. However, days of the week still heavily influence our lives and offer a way to connect across space and time. Modern English days of the week reflect a mixture of Roman, Anglo-Saxon, and Norse gods—resulting in a mixing pot of ancient culture. Modern calendars blend these factors together.

Following the history of these commonly used words offers deep insights. Insights beyond basic language. It allows a glimpse into the past. It sheds light on religions, deities, and cultures that could fade away. So next time you’re counting down the days until Friday happy-hour, remember to thank Venus, Freyja, or Frigg—the goddess of love from Roman, Anglo-Saxon, and Norse culture respectively—for her day.

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