Days of the week in Spanish: the seven names, IPA and usage

Where the Spanish day names come from

Five of the seven names are Roman gods who were also planets. The late Roman week gave each day to one of the seven moving lights in the sky, and Spanish kept five of them almost as Latin had them: dies Lunae for the Moon, dies Martis for Mars, dies Mercurii for Mercury, dies Iovis for Jupiter and dies Veneris for Venus. Drop the word dies and the Latin genitive turns, over centuries of speech, into lunes, martes, miércoles, jueves and viernes.

Look at the endings. Martes, jueves and viernes end in -es because the Latin genitives Martis, Iovis and Veneris did. Lunes and miércoles have no such excuse: the Latin forms were Lunae and Mercurii, and their final -s arrived later by analogy with the neighbours, so that all five working days end alike.

The weekend broke the pattern. Saturn's day, dies Saturni, survives in English Saturday, but Spanish replaced it with sábado, from Latin sabbatum, taken through Greek from the Hebrew shabbat, the day of rest. The Sun's day, dies Solis, lives on in English Sunday; the Church renamed it dies Dominicus, the Lord's day, and that is the origin of domingo.

Portuguese, next door, went further and dropped the gods altogether.

Capital letters, accents and plurals

Spanish writes the days of the week in lower case: hoy es lunes, nos vemos el viernes. A capital appears only at the start of a sentence or as part of the name of a holiday, such as Viernes Santo (Good Friday), Domingo de Ramos (Palm Sunday) or Miércoles de Ceniza (Ash Wednesday). English speakers capitalise them by habit, so a capital L on lunes in mid-sentence is a frequent slip in learners' writing.

Two names carry a written accent, miércoles and sábado. Both are stressed on the third syllable from the end, and Spanish marks every word stressed there. The other five are stressed on the second-to-last syllable and end in a vowel or -s, so they need no accent.

All seven are masculine. The five that end in -s do not change in the plural: el lunes, los lunes; el viernes, los viernes. Only the weekend days add an -s, los sábados and los domingos.

Abbreviations: why Wednesday is X

Calendars, school timetables and opening hours in Spanish use one letter per day: L, M, X, J, V, S, D. Martes and miércoles both begin with M, so Wednesday takes X and Tuesday keeps the M. A printed week therefore reads L M X J V S D, and a sign that says L–V means Monday to Friday.

Three-letter forms are the other common set: lun, mar, mié, jue, vie, sáb, dom. The Unicode CLDR locale data, which phones and computers use to print Spanish dates, contains both sets, so software set to Spanish usually prints these forms. In running text an abbreviation takes a full stop, as every Spanish abbreviation does: lun., mié.

How to use the days of the week in Spanish sentences

The English word on disappears. El lunes means on Monday, so te llamo el jueves is I'll call you on Thursday, with no preposition before the day. Adding en is a typical English speaker's error.

The plural article turns a single day into a habit. Los lunes tengo clase means I have class on Mondays, every week; todos los lunes says the same with more weight. The singular el lunes points to one Monday only, usually the next one.

When a sentence simply states the day, the article goes: hoy es martes, mañana es miércoles. It comes back as soon as the day answers when: el examen es el martes, the exam is on Tuesday.

For ranges Spanish uses de … a: de lunes a viernes. Entre semana means on weekdays, and el fin de semana is the weekend. Next and last attach to the day as el lunes que viene (or el próximo lunes) and el lunes pasado. Full dates keep the article and put the day first, el lunes 3 de marzo, written in lower case throughout.

Regional pronunciation and variants

The names are the same in every Spanish-speaking country. What changes is the sound. The j of jueves is a rough [x] at the back of the mouth in Spain and Mexico, and a soft breathy [h] in the Caribbean, most of Central America and Colombia. In Andalusia and the Caribbean a final -s is often breathed out or dropped, so lunes can sound like [ˈluneh].

Learners who know the Castilian [θ] of cena and plaza can relax here: none of the seven names contains a c before e or i, or a z, so Spain and Latin America pronounce them alike on that point. The letters b and v share one sound, [b] after a pause and the softer [β] between vowels. Viernes therefore starts like a b. The IPA chart shows every symbol in the table above.

Spain also has co-official languages with their own names. In Catalonia, Valencia and the Balearic Islands signs and timetables may use the Catalan forms dilluns, dimarts, dimecres, dijous, divendres, dissabte and diumenge, built on the same Latin roots with di- from dies at the front.

Far from Spain, Tagalog borrowed most of the Spanish week during colonial rule: Lunes, Martes, Miyerkules, Huwebes, Biyernes and Sabado, while Sunday is Linggo.

How the week is ordered in Spanish

In Spain and most of the Spanish-speaking world the week starts on lunes and ends on domingo. Printed calendars in Spain put lunes in the first column, which matches the international standard ISO 8601, where Monday is day 1 and Sunday is day 7. Some calendars printed in the Americas follow the United States layout and open the grid on domingo, so check the first column before reading a date off one.

The older Christian count made Sunday the first day of the week. Portuguese still shows it in its names: Monday is segunda-feira, the second day, and Friday is sexta-feira, the sixth. Spanish kept the planets and so lost that trace, apart from domingo itself.