Spanish uses the definite article with days of the week in a unique way. Instead of saying on Monday with a preposition, Spanish simply says el lunes — and this single article replaces the English word on. The number (singular vs. plural) decides whether you mean one specific day or a recurring one.
El + Day = On That Day
El + day refers to one specific occurrence of that day.
Nos vemos el sábado.
See you on Saturday.
Notice there is no separate word for on. The article el does that job all by itself.
Los + Day = Every Week on That Day
Los + day in plural means the action happens habitually every week.
Los lunes tengo yoga.
On Mondays I have yoga.
Los viernes salimos con amigos.
On Fridays we go out with friends.
| Form | Meaning |
|---|---|
| el lunes | on Monday (one specific) |
| los lunes | on Mondays (every week) |
| el sábado pasado | last Saturday |
| el próximo jueves | next Thursday |
If your English sentence says on Mondays (plural, habitual), use los lunes. If it says on Monday (one time), use el lunes. Spanish never uses a separate preposition for on with days.
Days that end in -s (lunes, martes, miércoles, jueves, viernes) look identical in singular and plural — only the article el or los tells you which.
No Article with Ser
When you are stating what today's day is, using the verb ser, you do not use an article.
Hoy es lunes, mañana es martes.
Today is Monday, tomorrow is Tuesday.
¿Qué día es hoy? Es viernes.
What day is today? It's Friday.
The rule: es lunes identifies the day; el lunes locates an action in time. These are two different jobs.
Dates: El + Number + De + Month
Full calendar dates use el + number + de + month. Months, like days, are not capitalized in Spanish and are all masculine.
Nací el 15 de mayo de 1990.
I was born on May 15, 1990.
El 5 de mayo es una fiesta mexicana.
The 5th of May is a Mexican holiday.
Spanish uses cardinal numbers for all dates (cinco, quince, treinta) except the first of the month, where you can optionally say el primero de or el uno de. El primero de enero and el uno de enero are both accepted. See Dates for more.
Telling Time: Las + Hour
Times also use the feminine article la or las (la hora, las horas are implied).
Son las tres de la tarde.
It's three in the afternoon.
La película empieza a las ocho.
The movie starts at eight.
- Singular la is used only for one o'clock: es la una.
- Plural las is used for all other hours: son las dos, son las diez.
See Telling Time for full details on a las, y cuarto, menos diez, and similar phrases.
Years: Also with the Article (Sometimes)
When talking about years as nouns, Spanish often uses the article: el 2020 fue difícil (2020 was hard). But in dates with days and months, the year stands alone without an article: el 15 de marzo de 2024.
Fue en el año 1492.
It was in the year 1492.
Quick Recap
- El + day = on that specific day; los + day = every week on that day.
- Days stay lowercase; so do months.
- No article after ser when stating the day: hoy es lunes.
- Dates use el + number + de + month, optionally el primero for the 1st.
- Times: es la una, son las [hour].
Common mistakes
❌ Voy en Lunes.
Wrong: use the article el, not the preposition en, for days.
✅ Voy el lunes.
Correct: el lunes means 'on Monday'.
❌ Hoy es el lunes.
Wrong: after ser stating the current day, drop the article.
✅ Hoy es lunes.
Correct: no article after ser + day of the week.
❌ Trabajo los Lunes.
Wrong: days of the week are lowercase in Spanish.
✅ Trabajo los lunes.
Correct: los lunes (lowercase) means 'every Monday'.
Related Topics
- Expressing DatesA1 — How to write and say Spanish dates — day, month, year
- Telling TimeA1 — How to ask and answer what time it is
- Definite Articles (El, La, Los, Las)A1 — The four forms of the definite article and how they agree with the noun's gender and number