"Calendar" Transcript

By Mark Sundaram

Welcome to the Endless Knot! We’re coming to the end of the year and the beginning of a new decade, and if you haven’t yet, you might be looking for a new calendar to keep track of the days, weeks, and months of the new year. But where do all those calendrical names of months and weekdays come from? Let’s find out!

The history of calendars can be traced back to the urban revolutions, when humans began to shift from small communities to large cities in the bronze age. These complex cities led to things like writing, currency, and standardized weighs and measures, which allowed for financial transactions and taxation, and calendars soon followed, which not only regulated human time important for agriculture and taxation, but also religious time important for festivals and other observances. First came the Sumerian lunisolar calendar, which was organized by both the solar and lunar cycles, followed by independent calendar systems developed in other parts of the world, such as the Egyptian solar calendar, early solar calendars in China, and the famously complex Mayan calendar in Mesoamerica, which led to the famous 2012 millenarian phenomenon because of the mistaken belief that the Mayan calendar predicted the end of the world in that year — in fact it was really just the end of a 5126 year long cycle tracked in their calendar, important but not apocalyptic.
The word calendar actually comes from the Roman calendar, in which the first day of the month was named the Kalendae or “Kalends”, traditionally spelled with a <k> even though the letter was very rare in classical Latin, from calare “to call, summon”, being the day when the priests would announce the new moon and declare the number of days, five or seven depending on the month, until the next named day, the nonae or “nones” meaning literally “nine”, which, if you count inclusively, that is counting both the day you start with and the day you end on, is nine days before the next named day, the idus, or “ides” (as in the famous ides of March when Julius Caesar was assassinated), etymology unknown but perhaps Etruscan, coming on either the 13th or 15th of the month, and all the other days of the month were simply counted back inclusively from these named days. Those named days, by the way, were likely originally there to mark the phases of the moon. For the Romans, the word for “year” was annus (from which we get annual), ultimately from the Proto-Indo-European root *at- “to go”, thus indicating the idea of the period of time gone through. The English word year comes from Old English gear, ultimately from the Proto-Indo-European root *yer- meaning “year, season”, which also came into Greek as hora “season”, which eventually found its way into English in the words horoscope, and hour indicating a very different unit of time. The word for month in most languages is usually connected with the word for moon, since a month was, originally at least, a cycle of the moon. The Romans called the month mensis, and our English word month, related to moon, comes from Old English monað, and all of these words can be traced back to the Proto-Indo-European root *me- “to measure”, also source of words such as measure, metre, moon, and menstruate.
We’ve already explored the details of the Babylonian and Jewish calendars, and how lunar, solar and lunisolar calendars work in our previous videos on the words “Sabbath” and “Millennial”, so if you want to learn even more about those topics, check them out, but to briefly summarize the key issues relevant to our modern calendar, the modern secular calendar is strictly solar, which keeps in sync with the solar cycle, determined by the earth’s orbit around the sun, so that the solstices, when the day or night is at its longest, and the equinoxes, when the day and night are the same length, occur at the same time every year. But as I mentioned before, there are other natural cycles that can be used in organizing a calendar, such as the daily cycle determined by the rotation of the earth, and the lunar cycle or lunation determined by the moon’s orbit around the earth. The problem is, none of the cycles line up properly. The year can’t be divided up into an even number of lunations (there’s about 29.53 days in a lunation, and about 12.38 lunations in a solar year), so luni-solar calendars that track both cycles have to cheat by adding in extra days or months here and there to reconcile the different cycles, what are known as intercalary days or months, intercalary meaning “inserted into the calendar” from Latin inter “between” and that same root as calendar. And in fact the year can’t even be broken down into an even number of days (it’s actually 365.24 days), hence our need for leap years.
Now although our secular calendar is not dependent on lunations, only needing to reconcile the daily and yearly cycles, since our modern calendar was in part developed by the Christian church, based on the Roman calendar and the Jewish calendar, we do also have bear in mind the lunar cycle when we look at its history. The 7 day week seems to have originally been derived from the phases of the moon in the Babylonian calendar, which was then transformed in the Jewish calendar to a simple repeating 7 day cycle ending in the Sabbath no longer tied to the lunar phases. But the Jewish calendar was nevertheless still a lunisolar calendar, and so festival days also depended therefore on lunation, and since the Christian tradition was based on Judaism, some of the Christian festivals are also based on the lunar cycle. This is why in the Ecclesiastical calendar, sometimes referred to as Kalendar with a <k> as in that ancient Roman tradition, there are movable feasts, based on the lunar cycle, and fixed feasts, based on the solar cycle. This is why Christmas, a fixed feast, occurs on the same date every year, but Easter, a movable feast, based on the lunar cycle, moves around.
So today we’re going to focus on how we got our modern international calendar, with the months and weekdays we know and love. And to do that, we have to start with classical Rome.

The Old Roman calendar originally had only ten months, starting with March and ending with December, with a number of intercalary days after December to reconcile the calendar with the solar year, and later on these intercalary days were replaced with two new months, January and February, and the start of the year was eventually moved to the beginning of January. But this is why the months September, October, November, and December, which etymologically come from the Latin numbers septem “seven”, octo “eight”, novem “nine”, and decem “ten” are no longer the seventh, eighth, ninth, and tenth months. That original Roman calendar was modified over and over again, with the length of months becoming fixed so that they no longer represented lunar cycles, and it was brought more in line with the solar cycle, for instance by adding leap days, as we have it now. Every year divisible by four contains a leap day, unless the year is divisible by one hundred in which case it isn’t a leap year, unless the year is divisible by four hundred in which case it is a leap year again. Got that? It was the Roman Julius Caesar, who had that unlucky day in March, who originally added the leap day every four years, in the year 46 BCE, hence it’s called the Julian calendar, but since the year is slightly less than 365 and a quarter days long, Pope Gregory XIII promulgated the current more complex system of leap years in 1582, hence our calendar now is called the Gregorian calendar, though it was actually the work of physician and astronomer Aloysius Lilius, with further refinements by Jesuit German mathematician and astronomer Christopher Clavius, who by the way first introduced brackets in mathematics and was one of the first to use the decimal point in the West. But that explains why historical dates are sometimes messed up. Because in order to get the calendar back on track from the 10 day difference that had built up since the Julian calendar started being used, in 1582 October 4th was followed immediately by October 15th. And to make matters worse, only Catholic countries adopted the new calendar in 1582, with Protestant and Orthodox countries only adopting it some time later, leading to many discrepancies. Britain didn’t adopt the new calendar until 1752, by which point the slippage had increased to 11 days, so in Britain in 1752, September 2nd was followed by September 14th. And of course many at the time complained about the “loss” of those 11 days. You can imagine this would be a financial problem, calculating things like interest for instance. Some Orthodox churches are still a number of days out, which is why Orthodox Christmas is on January 6th, though most traditionally Orthodox countries have finally switched to the Gregorian calendar for secular purposes, but often only relatively recently, with Russia switching only in 1918, and Greece as late as 1923. The other confusing element about historical dates is the fact that the date of New Year’s Day, when the numerical year would tick over, kept switching around. Julius Caesar moved it from March to January 1st, once those new months were created, but under the influence of Christianity it was often moved to various days of religious importance, such as Christmas, the Annunciation in March, or Easter, but the Gregorian reform moved it back to January 1st, and non-Catholic countries often only switched once they adopted the new calendar. But all this is for instance why the Russian October Revolution actually took place in November.
So as we’ve seen, the names September, October, November, and December are simply derived from the Roman numbers, and those are by the way cognate with our English numbers, coming from the Proto-Indo-European numbers *septm-, *okto-, *newn-, and *dekm- respectively. The -ber ending on those months, by the way, is of uncertain etymology: it might be related to mensis “month”, which would then have produced a form *-mensris and then *-membris, or it might simply be from the Latin adjectival suffix -bris from the noun suffix -bra or -brum, ultimately from the Proto-Indo-European noun-forming suffix *-dhrom. But what about the other months of the year? Well let’s start with January or Ianuarius in Latin which is named after the two-faced god of doorways Janus, very appropriate for the newly instituted first month of the year. The name Janus or actually Ianus in Latin is related to the word ianua “door” which gives us English janitor, who was originally a doorkeeper, and comes from the Proto-Indo-European root *ie- “to go”, which might lie behind the root *yer- and would thereby be related to the word year, also appropriate. Now the early Germanic peoples had their own calendar system too, and some of those old month names continued to be used for a while before being replaced by the Roman names, so in Old English December and January roughly coincided with Geolamonaþ or “Yule month” in reference to the old pagan festival Yule now associated with Christmas, and later was divided up into two months Ærra-Geolamonaþ “before Yule month” for December and Æfterra-Geolamonaþ “after Yule month” for January, and you can learn more about the etymology and significance of Yule in our “Yule” video. Yuuuule love it!
Next up is February, the other “new” month that the Romans added to their originally ten month calendar. Since Februarius was the last month in the Roman calendar until the first month was changed from March to January, there were a number of Roman festivals then that were concerned with endings and boundaries, such as Parentalia which involved honouring ancestors and propitiating the dead, and Terminalia a festival in honour of Terminus the god of boundaries. Another festival in Februarius was the purification ritual known as Februa or Lupercalia, and it’s from this that the month takes its name. Februa is the plural form of februum meaning “means of purification, expiatory offerings”, presumably some sort of instrument used in the purification ritual. In his calendar poem called the Fasti, Ovid suggests the word comes from an “ancient tongue” presumably Etruscan or possibly Sabine, another Italic language related to Latin, but ultimately the etymology of the word is unknown. It might come from the Proto-Indo-European root *dhegwh- “to burn, warm” also the source of the word fever, or the root *dheu- “dust, vapour, smoke” also the source of the word fume, either way suggesting a ritual involving fire and/or smoke. In the Germanic calendar, February is equivalent to Solmonaþ, which the Venerable Bede, in his De temporum ratione or The Reckoning of Time, explains means “month of cakes” because the English used to offer cakes to their old Germanic gods in that month, though some scholars have suggested that instead it might mean “mud month” since “mud” is the usual meaning of the word sol, and that time of year is particularly wet in the climate of England. Bede, by the way, was one of the foremost Latin writers in early medieval England, and his De temporum ratione, which not only gives and explains the Latin and Old English names of the months, but also the Hebrew and Greek names, is a work about computus, that is the calculation of the calendar, and specifically the calculation of the date of Easter, which moves around every year since it’s based on a lunar calculation, unlike most of the rest of the Christian calendar. There was a controversy about the method of calculating Easter just prior to Bede’s time revolving around whether the English should calculate Easter following the methods of the church in Rome or following the Irish church’s method. Bede was a staunch supporter of the Roman church, so the climactic moment of Bede’s most famous work Historia ecclesiastica gentis Anglorum or Ecclesiastical History of the English People was when the Synod of Whitby decided in favour of the Roman method of calculation, as well as the Roman form of tonsure or haircut instead of the Irish. The other thing Bede’s Historia ecclesiastica achieved was popularizing the system of BC and AD years, which we discussed in the “Millennial” video. As for the calculation of Easter, it was originally tied to the Jewish Passover — the Last Supper of Jesus and his disciples before the crucifixion is presented in at least some parts of the New Testament as a Passover seder. But because Passover moves around so much in relation to the solar Roman calendar and also because the early Christian church wanted to distance themselves from Judaism, their calculation is instead based on the equinox and the full moon, that is the Sunday following the full Moon which falls on or after the equinox, though even that isn’t exactly how the calculation works.
Now moving on to March or Martius in Latin, this month is named after the Roman god of war Mars, appropriate since it was typically the opening of the military campaign season, who was held to be the progenitor of the Roman people as father of the legendary founders of Rome, Romulus and Remus, and who became associated with the Greek god of war Ares. This is a process known as syncretism, when one tradition is understood by interpretation and comparison to another tradition. In this case Romans reinterpreted their native gods by comparison to the Greek gods reconciling the two traditions, thus it is specifically known as interpretatio graeca. So since Mars was understood as a god of war, he was seen as equivalent to the Greek Ares who had the same role, and thus the Romans borrowed the rich tradition of mythological stories associated with Ares. The word syncretism, by the way, has a surprising etymology, coming from Greek synkretismos, from the prefix syn- “with, together” and a debated second element, possibly the the name of the island of Crete, because the earliest attested use of Greek synkretismos is to refer to a federation of Cretan communities, though some have also suggested a connection to Greek krasis “mixture”. As for the name Mars, its source is uncertain, but it may be connected to the Etruscan god Maris. And as for Mars himself, he seems to have originally been a thunder god, not a god of war, and may descend from an old Indo-European god of thunder and oak trees, *Perkwunos meaning literally “oak”, also the source of the Germanic god Thor, though the name *Perkwunos was transferred to Thor’s mother Fjörgyn. The connection between thunder and oak may be that lightning has a tendency to strike the very tall oak trees. As for the name of the month of March in the Germanic calendar, Hreþmonaþ, this refers to a different god, Hreðe, to whom Bede tells us the English sacrificed at this time. We know nothing more about this goddess, but her name seems to mean either “victorious” or “famous” related to Old English hreð “glory (in battle), victory” and from the same root as the first element in the names Rudolph literally “famous-wolf” and Roger “famous-spear”.
Next is April or Aprilis in Latin, which marks the beginning of spring, and one traditional etymology reflects this, with Aprilis coming from Latin aperire “to uncover, open”, from Proto-Indo-European *apo- “off, away” and *wer- “to cover”, since all the plants open up at this time of year. Ovid mentions this etymology, but also provides a different derivation, that since it is the month of the goddess of love Venus with her festival on the kalends, the name comes from the Greek equivalent Aphrodite. This could make sense coming through Etruscan Apru, a borrowing of the shortened version of her Greek name Aphro. Now the name Aphrodite is itself of uncertain origin, but Ovid goes on to mention the usual Greek understanding of her name that it comes from Greek aphros “foam”, because of the myth of her origin from sea foam produced by Uranus’s genitals when his son Cronus cut them off and threw them into the sea. The word aphros in turn might come from the Proto-Indo-European root *nebh- “cloud”, also the source of nebula, nimbus, and Neptune, the Roman sea god who became syncretized with Greek Poseidon. The second element of Aphrodite might be related to Greek deato “seemed, appeared” and delos “clear, visible” (also the source of the second element in psychedelic) from Proto-Indo-European *dyeu- “to shine”, suggesting she might originally have been a dawn goddess. More recent arguments, however, generally derive Aphrodite’s name from a pre-Greek language, as the goddess herself seems to be largely influenced by eastern cults of the Phoenician Astarte, cognate with Babylonian Ishtar, herself influenced by Sumerian Innana, so a lot of syncretism going on there. A completely different etymology for the name of the month Aprilis is that it might come from an otherwise unattested form *aperilis meaning “the following, the next” ultimately from that same Proto-Indo-European *apo-, since it was the second month in the older Roman ten month calendar. According to Bede, the Germanic name for April is Eosturmonaþ or Easter month, named after an old Germanic goddess Eostre who is celebrated in that month. The Germanic name was then borrowed to refer to the Christian festival of Christ’s crucifixion and resurrection. Most non-Germanic languages refer to Easter with some form of the semitic word for Passover, which is Aramaic Paskha and Hebrew Pesach, literally “he passed over” in reference to the story in Exodus in which the spirit of God passed over the homes of the children of Israel in Egypt while inflicting the tenth plague of the death of the Egyptian first-born. Thus for instance the word for Easter in French is Pâque, in Italian Pasqua, and in Spanish Pascua, but in German it’s Ostern. As for the goddess Eostre, we don’t know very much about her, though the name is attested in the month names of a number of other Germanic languages, as well as in some placenames and other fragmentary evidence. Etymologically it seems to be traceable back to the Proto-Indo-European root *aus- “to shine”, also the source of the word East, and thereby identified as a descendant of a Proto-Indo-European dawn goddess *Hausos, also the source of the Roman goddess Aurora, the Greek goddess Eos, the Vedic goddess Usas, and the Lithuanian goddess Ausrine.
Next up is May or Maius in Latin, named after the Roman earth goddess Maia, who might be related to or have become conflated with the Greek goddess of the same name. The Greek Maia was the daughter of the Titan Atlas and the mother of Hermes, equivalent to Roman Mercury. The Roman Maia is also said to be the wife of the blacksmith god Vulcan, equivalent of the Greek Hephaestus. Maia also became connected with the mystery cult goddess referred to as Bona Dea meaning “Good Goddess”, though her actual name was only known to women, so the Roman male authors didn’t know much about her or the rituals associated with her. The Romans saw Maia as a goddess of growth, deriving her name from the comparative adjective maius, maior “larger, greater”, from which we get the word major. The Greek word maia, on the other hand, was an honorific term for older women, perhaps derived from mater “mother”. However, both the Greek and Latin names might simply mean “she who is great” from the Proto-Indo-European feminine form *mag-ya-, from the root *meg-, which is in any case the root that lies behind Latin maius. Bede tells us that the Germanic name for May is Þrimilcemonaþ literally “three milk month” because in that month cows can be milked three times a day.
June or Iunius in Latin was the last originally named month in the old Roman calendar, the rest simply being numbered. Ovid has three different goddesses claiming the month as theirs, giving three possible etymologies for Iunius. In the first, the one that most modern etymologists agree with, the goddess Juno wife of Jupiter, syncretized with Greek Hera and Zeus, says the month is named after her. The name Juno either comes from that same root *dyeu- meaning “to shine” that we saw in connection to Aphrodite with the sense “sky, heaven” plus *en-es- “burden”, from which we get the word onus, thus forming a compound meaning “having heavenly authority”, or from the root *yeu- “vital force, youthful vigour”, which also gives us the words youth and young. Then the goddess of youth and rejuvenation Juventas says the name comes from iunior “young person”, from which we get the word junior, in contrast to maiores or “elders” which she says is the actual source of the name of the month Maius. This etymology would also ultimately come from the root *yeu-. And finally the goddess of marriage and society, Concordia, says the name comes from the word iungere “to join” in honour of her uniting the Romans and the Sabines. Latin iungere comes from the Proto-Indo-European root *yeug- “to join”, which also gives us the words join, yoke and yoga, through Sanskrit, because yoga involves the joining with the supreme spirit. Another theory is that it comes from the name of the Iunia clan, either after Marcus Junius Brutus who made the first sacrifice to the goddess Carna on the kalends of June, or Lucius Junius Brutus, the founder of the Roman republic who overthrew the last of the Etruscan kings and became one of the first Consuls of Rome. The clan name Iunia is probably itself connected with the goddess Juno. Bede tells us both June and July are called Liþa from liðe “mild” because both the months are mild and feature gentle breezes suitable for navigating on the sea. Ultimately the word comes from the Proto-Indo-European root *lent-o- meaning “flexible” also the source of the words lithe and relent.
Now it’s interesting that we just mentioned Marcus Junius Brutus, because there’s another more famous Marcus Junius Brutus who is connected with the month of July. July was originally called Quintilis just meaning the “fifth” month, but was renamed in honour of Julius Caesar in 44 BCE, and the sixth month, originally Sextilis, was renamed Augustus in honour of Caesar’s adoptive son, the first Emperor of Rome, in 8 BCE. You see when Julius Caesar was making his power grab people were worried he would make himself king and end the republic, and so there was a conspiracy to assassinate him. One of the conspirators, as you may remember from Shakespeare’s play, was Marcus Brutus: “Et tu Brute?” Brutus’s full name was Marcus Junius Brutus, also a member of the Iunia clan, and purported descendant of Lucius Junius Brutus who founded the republic, so as you can imagine Marcus Brutus, most definitely an “honourable man”, felt a certain pressure to defend that republic. The Julius of Julius Caesar is another of those clan names, the gens Iulia, and it is probably a contraction of Old Latin *Iovilios “pertaining to or descended from Jove”, Jove being another form of the name Jupiter. Jove goes back to that same root *dyeu- “to shine” which has a number of derivatives in the various Indo-European languages that mean either “sky” or “god”, such as Latin deus “god” and Greek Zeus, suggesting the existence of an Indo-European god *Dyeus who would have been the father of the dawn goddess *Hausos. Jupiter is derived from a vocative compound *dyeu-pəter meaning something like “O Father Jove”. Augustus was actually an honorific title given to the first emperor, who was born Gaius Octavius Thurinus, meaning “august” or “venerable”, and either comes from Latin augere “to increase” from the Proto-Indo-European root *aug- “to increase” also the source of augment and wax as in a waxing moon, or might be related to augur, as in augury (fortune telling through birds), which itself might come from the root *aug-, or might come from the root *awi- “bird” also the source of the words aviary and egg. For the English it was Weodmonaþ literally “Weed Month” though more broadly and accurately “Plant Month”, because as Bede tells us they grow most abundantly in that month.
Now as we’ve already said September through December are just numbered months. According to Bede September was called Haligmonaþ “Holy Month” but it is also called Hærfestmonað “Harvest Month” according to another early English writer Ælfric. October was called Winterfylleþ literally “Winterfull” because as Bede explains winter begins on the full moon of that month. November is called Blotmonaþ meaning “Sacrifice Month” or “Blood Month” because cattle were to be slaughtered and sacrificed to the gods then, and if you want to know more about that, and the names of the seasons, you can check out our video on the word “Feast”. And finally as we’ve already seen December is part of Geolamonaþ.

Moving down from the month, we have the week, which roughly represents the four phases of the moon. Another numerical reason for the seven day week is perhaps the fact that the year breaks down into 52 weeks plus one day. The word for “week” in European languages is usually related to the number seven, as in Greek hebdomas and Latin septimana from septem, from which comes French semaine and Spanish semana. The English word week, on the other hand, is Germanic-derived, from Old English wuku, ultimately from Proto-Indo-European *weik- “to bend, wind” (which also gives us the other word weak) probably in the sense of “turning” or “succession”, though there’s no clear evidence that it referred to a period of seven days in Germanic culture until after the influence of the Roman week. The Romans themselves didn’t originally have a week in their calendar system, as we’ve seen it was really organized by counting back from the various named days, though they did have an 8-day market cycle. We have to go back to Babylonian astrology to really understand where the weekday names come from. You see the Babylonians associated the planets visible to the naked eye (since there were no telescopes back then) with gods, and this may have inspired the Hellenistic Greek astrologers. Some of them even seem to line up in syncretic associations, with the chief Babylonian god Marduk associated with the planet Jupiter, and the goddess of love, beauty, and sex Ishtar, whom we’ve already seen connected with Aphrodite, associated with the planet Venus. For the Hellenistic astrologers there were seven planets, since they included the moon and sun, which moved across the sky relative to the “fixed” stars. And eventually these seven classical planets became associated with the seven days of the week, which were eventually adopted by the Romans from Hellenistic Greece and called dies Solis “day of the Sun” or “Sunday”, dies Lunae “day of the Moon” or “Monday”, dies Martis “day of Mars” or “Tuesday”, dies Mercurii “day of Mercury” or “Wednesday”, dies Iovis “Day of Jove” or “Thursday”, dies Veneris “day of Venus” or “Friday”, and dies Saturni “day of Saturn” or “Saturday”. But why this order? Well, the order that they placed the planets in in terms of distance from the Earth was based on their apparent speed moving across the sky, so in order of slowest to fastest Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon, called the Chaldean order, but that’s not the order of the days of the week. The answer lies not in assigning the planets to the days of the week directly but in assigning them to the hours of the day, called planetary hours in which each planet/god had power over that hour, and there’s some evidence to suggest that the Hellenistic astronomers got this idea from the Babylonians as well. If you start with Saturn on the first hour of the first day and cycle through all the seven planets in the Chaldean order, then start over with Saturn on the eighth hour, and so on, and then continue that pattern hour-by-hour over the seven days of the week, each day will begin with a different planet in the order of the days of the week as we’ve just seen in the Latin names.
Now let’s look at the etymology of each day specifically. First of all Sunday or dies Solis in Latin, originally hemera Helíou in Greek, which was later rendered Sunnandæg in Old English and Sunnudagr in Old Norse, with all of these words for the sun and correspondingly for the personification of the sun in each pantheon, with Sol in Latin and Helios in Greek coming from the same Proto-Indo-European root *sawel- “sun”. The word helium, by the way comes from the Greek word, because the element helium was first detected in the sun through spectroscopic observation of a solar eclipse. Now you might assume that the words for “day” are all related too, but surprisingly not. First of all Greek hemera, from which we get the English word ephemeral, comes from the Proto-Indo-European root *amer- “day”, whereas English day, from Old English dæg, comes from an unrelated root, probably *agh- “day”, though the initial /d/ in the Germanic forms is hard to account for, or *dhegwh- “to burn, warm”, which we’ve already seen as possibly lying behind the month name February. And though Latin dies looks superficially similar to English day, it actually comes from that root *dyeu- meaning “to shine”. Now in the Romance languages derived from Latin, that original name connected to the sun was replaced with forms derived from Latin dies Domini “day of the Lord”, so domingo in Spanish and dimanche in French.
For Monday, or Monandæg in Old English and Mánadagr in Old Norse, we’ve already seen that moon, as well as month, come from *me- meaning “measure”. Latin Luna, from which we get lunar, comes from the Proto-Indo-European root *leuk- “light, brightness”, also the source of light, illuminate, and lucid, and from Latin dies Lunae come French lundi and Spanish lunes. And Greek Selene, Moon, is related to selas “light” from the root *swel- “to shine, burn” also source of English sultry and swelter. The Roman goddess Luna, by the way, was said to be the sister of the sun god Sol and the dawn goddess Aurora, who as we’ve seen might be related to the Germanic goddess Eostre.
Now things start to get particularly interesting with Tuesday, which is dies Martis or “day of Mars” in Latin, which leads to French mardi and Spanish martes. The Greek equivalent is of course hemera Areos, or day of Ares, the Greek god of war, whose name comes from the Greek word are “bane, ruin, curse”, perhaps from Proto-Indo-European *eis- which seems mean “to move rapidly” and is found in words denoting passion, also leading to such words as ire, iron, and estrogen. Through the process of interpretatio germanica, the Roman war god became associated with the Germanic war god Tiwaz, who becomes Tyr in Old Norse and Tiw in Old English, thus producing the weekday names tysdagr in Old Norse and Tiwesdæg in Old English, leading to Modern English Tuesday. Interestingly though, Tiwaz was not originally a war god, but instead descends from the Proto-Indo-European god *Dyeus who also lies behind Zeus and Jupiter. Tiwas may originally have been a more prominent god in the Germanic pantheon, but his role seems to have been usurped somewhere along the line by the god Odin, who is the subject of our next day of the week.
Wednesday, from Old English Wodnesdæg, is named after the Germanic god Woden, more famously known by the Old Norse form of his name Odin, hence Old Norse óðinsdagr. This is a syncretic rendering of Latin dies Mercurii “day of Mercury”, which becomes French mercredi and Spanish miércoles. But what’s the point of comparison between the chief Norse god and Mercury, the Roman equivalent of Hermes, the Greek messenger god? Well one of Hermes’s responsibilities was to guide the souls of the dead to the afterlife, a position called a psychopomp. Odin too is associated with the dead, playing host in Valhalla in the afterlife to warriors who died in battle. Also, when Odin travelled amongst humans on Midgard he wore a broad-brimmed hat and cloak and carried a staff, which was visually similar to the appearance of Hermes, who was also a god of travellers, merchants, and commerce. The name Hermes is probably connected to the Greek word herma “heap of stones, boundary marker” because of the god’s associations with travellers, but the ultimate etymology of that word is unknown, possibly from a non-Indo-European root, though a connection to the Proto-Indo-European root *ser- “to line up, bind together” has been suggested. Interestingly, Hermes is thought to have originated as a form of the Greek pastoral god Pan, taking on the boundary marking associations and leaving Pan with the rustic associations. Pan is thought to descend from an original Indo-European god *Pauson, with the name ultimately coming from the root *pu- “to blow, swell” also leading to the words pustule and prepuce, another word for foreskin. Getting back to the Roman equivalent Mercury, the root sense of his name seems to be connected specifically to commerce, probably being related to such words as merchandise and market, coming ultimately from either the Proto-Indo-European root *mark- meaning “to grab” or to an Etruscan root referring to aspects of commerce, though another possible connection might be to the Proto-Indo-European root *merg- meaning “boundary, border”, which also gives us the words margin and mark as in a boundary mark. Odin’s name, however, demonstrates a rather different association, being related to Old Norse óðr, “mad, frantic, furious”, and coming ultimately from the Proto-Indo-European root *wet- meaning “blow, inspire, spiritually arouse”, which also gives us the words fan and atmosphere.
Thursday, Þunresdæg in Old English and þórsdagr in Old Norse, is named after the Germanic thunder god Thor, and it’s not hard to see the connection between Thor and the Roman and Greek gods Jupiter and Zeus, as they are all associated with lightning. Latin dies Iovis “Day of Jove” became French jeudi and Spanish jueves. As we’ve already seen, the names Jove, Jupiter, and Zeus all descend from that Indo-European sky god Dyeus, who in the Germanic pantheon becomes Tiwaz of Tuesday. As for Thor’s name it’s simply related to the word thunder, from the Proto-Indo-European root *(s)tene- “to thunder” that also gives us the words tornado, astonish, detonate, and stun.
Friday is dies Veneris “day of Venus” in Latin and hemera Aphrodites “day of Aphrodite” in Greek, named after the Roman and Greek goddesses of love, becoming vendredi in French and viernes in Spanish. We’ve already looked at the etymology of Aphrodite, and the etymology of the name Venus, from which we get the word venereal as in venereal disease, is pretty straightforward, coming from the Proto-Indo-European root *wen- “to desire, strive for”, also source of the words win, wish, and venerate, but also of venom, which originally referred to a love potion rather than a poison. However the Germanic association is somewhat complicated by the fact that there are two distinct but similar goddess Frigg and Freyja. The goddess who gives her name to Friday, Frigedæg in Old English and frjádagr in Old Norse, Frigg in Old Norse and Frige in Old English, is the wife of Odin and particularly associated with married love. Her name is similar to, and sometimes confused with, the goddess named Freyja, goddess of love and beauty, also connected with fertility. Well, you can see why they might be identified with each other, and it has been suggested that they might originally have referred to the same goddess. Interestingly, the name Freyja, only attested in Scandinavian sources, comes from a Proto-Germanic root that means “lady”, a root that also leads to modern German Frau, ultimately from the Proto-Indo-European root *per- meaning “forward”, whereas Frigg goes back to the Proto-Indo-European root *pri- that means “to love”, also giving us the words friend, free, and afraid (which means literally “out of peace”).
And finally we come to Saturday, which is dies Saturni “day of Saturn” in Latin. As seems clear from the Old English form Sæternesdæg and Modern English Saturday, the English didn’t seem to have a close equivalent to the Roman agricultural god Saturn and just borrowed the name instead. Saturn was associated with the Greek god Kronos, one of the Titans and father of Zeus, and also a god of agriculture. The etymology of Kronos’s name is uncertain, though many suggestions have been made ever since the ancient world, including the ancient association of Kronos with the similar sounding Chronos, the personification of time, which I suppose does make sense in terms of an agricultural god being concerned with time in terms of the seasons of the year, and the more recent suggestion that Kronos comes from the Proto-Indo-European root *(s)ker- “to cut” since he’s often depicted with a scythe not only because of agricultural associations, but also because of his role in the Greek creation myth of castrating his father Ouranos, the sky, from whom we get the (later) planetary name Uranus. As for the Roman Saturn, he may be a borrowing of the Etruscan god Satre, though the Romans themselves suggested an etymological connection with the Latin word satus meaning “sown”, as in sowing seeds, which comes ultimately from the Proto-Indo-European root *se- “to sow”, also source of the words sow, seed, and season. Now in Old Norse, instead of just borrowing the name from Latin, we find the day name laugardagr meaning “wash day”, which by the way puts paid to another of those medieval myths, that people in the middle ages bathed only once a year — there was literally a day of the week named after this activity! Interestingly, in most Romance languages, the Latin name was replaced with some form of the word Sabbath, as in French samedi and Spanish sábado, and for the complex etymology of that word, check out our previous video on the topic.

So now that we’ve covered the days of the week, let’s take one last quick look at another type of calendar, particularly appropriate to this time of year — an Advent Calendar, counting down the days of the Advent season leading up to Christmas. The tradition of the Advent calendar has its foundations in the German Lutheran homes in the 19th century, in which they might mark chalk or paint lines on the floor leading up to Christmas, or hand different devotional pictures on the wall, or light a new candle every day from December 1st until Christmas. Then, homemade advent calendars started appearing around 1850, which included a bible verse, drawing, or even a sweet for each day. The first commercially produced printed advent calendar was published in 1903 by Gerhard Lang, designed by Richard Ernst Kepler, called Münchener Weihnachtskalender or “Munich Christmas calendar”. And today there are many kinds of Advent Calendars, not only the ones with little chocolates behind cardboard doors, but also online Advent Calendars, including our own etymological Endless Advent Calendar on Twitter, Instagram, Tumblr, and Facebook!
And of course, the Advent Calendar ends with Christmas, closely followed by New Year’s (at least in some calendars!), which brings us back to January, where we started this etymological journey. And one thing this journey through the calendar has shown is how very classical its roots are — and that’s fitting, given the origin of “classical” itself. The words class and classical come from Latin classis which originally referred to the Roman people under arms, in other words the army or fleet. The underlying sense is a “call to arms” as the word comes from Proto-Indo-European *??kelə- meaning “to shout”, the same root that lies behind Latin calare “to call, summon”, and thus also the word calendar And this classically-based calendar has been changed and adapted many times to reconcile different gods, religions, and natural cycles of the sun, moon, and seasons — also fitting, since reconcile is another descendant from that same “shouting” root, coming from Latin reconcilare “to bring together again; regain; win over again, conciliate” from the prefix re- “again” and concilare “to make friendly”, from concilium “a meeting, a gathering of people”, from the prefix com- “together, together with” and that “shouting” root, with the notion of “a calling together”. And the root *??kelə- also comes into Greek as kalein “to call” and prefixed with ek- “out” as ekkalein “to call out”, which led to the noun ekklesia, which in Classical Athens was the principle assembly of Athenian democracy, but was later used by early Christians to refer to a religious assembly or the Christian Church as a whole, and from that we get the word ecclesiastical—as in the Ecclesiastical or Church Kalendar and Bede’s Ecclesiastical History of the English People. And with that, I hope this has made the origins of the modern calendar very clear — to draw on yet another word from the root *??kelə-. And if you’re celebrating around this time of the year, we at the Endless Knot wish you a happy Yule and happy New Year — and a calendar filled with fun and relaxation!

Thanks for watching! This concludes a three-video series on calendars, so if you haven’t yet, why not have a look at our previous videos about the words Sabbath and Millennial! It’s also part of an ongoing series of videos about time and language, so check out that playlist as well! If you’ve enjoyed these etymological explorations and cultural connections, please subscribe, & click the little bell to be notified of every new episode. And check out our Patreon, where you can make a contribution to help me make more videos. I’m @Alliterative on Twitter, and you can visit our website alliterative.net for more language and connections in our podcast, blog, and more!