Unlike its Spanish, French, and Italian cousins, Portuguese eschewed the standard Roman naming convention for its weekdays. The story behind this linguistic quirk is a fascinating journey into religious history, ecclesiastical law, and a deliberate cultural rebranding that has lasted for over 1,500 years.
The Usual Suspects: A Planetary Problem
To understand why Portuguese is different, we first need to look at the “normal” system for Romance languages, which itself is inherited from the Romans. The Romans named the days of the week after the seven celestial bodies they could see, which were in turn named after their gods:
- Monday: Day of the Moon (Dies Lunae) → Spanish Lunes, French Lundi, Italian Lunedì.
- Tuesday: Day of Mars (Dies Martis) → Spanish Martes, French Mardi, Italian Martedì.
- Wednesday: Day of Mercury (Dies Mercurii) → Spanish Miércoles, French Mercredi, Italian Mercoledì.
- Thursday: Day of Jupiter (Dies Iovis) → Spanish Jueves, French Jeudi, Italian Giovedì.
- Friday: Day of Venus (Dies Veneris) → Spanish Viernes, French Vendredi, Italian Venerdì.
(English, being a Germanic language, swapped the Roman gods for their Norse equivalents, like Týr for Tuesday, Odin/Woden for Wednesday, and Thor for Thursday, but the planetary principle remains.)
This pagan system was the standard across the Roman Empire. As the empire dissolved and Christianity spread, these names stuck. For most of Europe, the church simply accepted these deeply ingrained terms. But not in one particularly pious corner of the Iberian Peninsula.
Enter Saint Martin: The Braga Reformation
The man responsible for Portugal’s unique weekdays is Saint Martin of Braga (São Martinho de Dume), a 6th-century bishop in what is now northern Portugal. Martin was a tireless evangelist who was determined to stamp out paganism, which he saw as a form of demonic worship. He was particularly offended by the idea of Christians referring to the days of Holy Week (Semana Santa) by the names of Roman gods.
In his writings, particularly De Correctione Rusticorum, he argued that it was improper to honor “the day of Mars” or “the day of Mercury.” His solution was to introduce a new, purely ecclesiastical system for naming the days.
He drew inspiration from the Latin term feria, which was used by the church to denote a “day of rest.” In ecclesiastical Latin, the days of Easter week were already referred to as Feria Secunda, Feria Tertia, and so on, signifying the second day of the week, the third day, etc. Martin of Braga advocated for extending this naming convention to every week of the year.
So, What Does ‘Feira’ Mean Anyway?
The word feira today means “fair” or “market” in Portuguese. This seems like an odd fit. The connection is that holy days, or feriae, were days of rest from servile labor. These days of rest often became the days when people would gather, go to church, and, naturally, hold markets. Over time, the name for the holy day became associated with the market held on that day. In the context of the days of the week, however, -feira is a fossil word—a relic that simply means “day” within this specific numbered sequence.
The Full Lineup: Your Guide to the Portuguese Week
Martin of Braga’s system was adopted and eventually became the standard throughout the Portuguese-speaking world. Here’s how it works, keeping one crucial detail in mind: in the Christian tradition, the week begins on Sunday.
- Domingo (Sunday): This name was not part of the feira system. It comes from the Latin Dies Dominicus, meaning “The Lord’s Day”, and was already widely accepted by the church. This is the first day of the week.
- Segunda-feira (Monday): The second day of the week. (Secunda Feria)
- Terça-feira (Tuesday): The third day of the week. (Tertia Feria)
- Quarta-feira (Wednesday): The fourth day of the week. (Quarta Feria)
- Quinta-feira (Thursday): The fifth day of the week. (Quinta Feria)
- Sexta-feira (Friday): The sixth day of the week. (Sexta Feria)
- Sábado (Saturday): Like Sunday, this day falls outside the numbered system. Its name comes from the Hebrew Shabbat (Sabbath) via the Latin Sabbatum, a name also adopted by the church.
The Big Question: Where is ‘Primeira-Feira’?
This brings us back to our original question. Why isn’t Monday “Primeira-feira”? The answer is simple: the first day of the week, Sunday, already had a pre-eminent, non-pagan name: Domingo, the Lord’s Day. It was the most important day and stood on its own. The numbered “fair days” only began on the day *after* the Lord’s Day. So, Monday is the *second* day of the ecclesiastical week, hence segunda-feira.
Making it Stick: Mnemonics to Master the Feiras
Understanding the history is one thing; remembering it in conversation is another. Here are a few tricks:
1. The Simple Count
This is the most direct method. Just connect the Portuguese number to the day number (remembering that Monday is #2):
- 2 (dois/duas): Segunda-feira
- 3 (três): Terça-feira
- 4 (quatro): Quarta-feira
- 5 (cinco): Quinta-feira
- 6 (seis): Sexta-feira
The link between quatro/quarta and quinto/quinta is very clear. Sexta is also very close to seis. You just need to lock in segunda and terça.
2. The Work Week Anchor
If you’re stuck on Monday being “second”, think of it this way: Sunday is Day 1 of the week, but Monday is Day 1 of the work week. From there, you just count up. This mental shift can help bridge the gap between cultural calendars.
A Linguistic Lone Wolf? Not Entirely.
While Portuguese is the only major Romance language to use this system in daily life, it’s not entirely alone. Galician, spoken just north of Portugal and closely related to Portuguese, uses the same system (though sometimes with the pagan names as alternatives). And, of course, the system is still used in ecclesiastical Latin by the Catholic Church.
What makes Portuguese remarkable is that this religious, liturgical naming convention completely replaced the old pagan one and became the standard for secular, everyday use across an entire language and its global diaspora.
A Window into Culture
So, the next time you schedule a meeting for quarta-feira, take a moment to appreciate the history packed into that simple word. It’s not just the fourth day of the week; it’s a 1,500-year-old linguistic fossil, a testament to a bishop’s fight against paganism, and a perfect example of how language is a living museum, preserving the cultural and historical priorities of the people who shaped it.