Months in Spanish: the twelve names, pronunciation and writing a date

From Ianuarius to diciembre: the Latin calendar inside the Spanish months

Every one of the twelve Spanish month names comes from the Roman calendar. Spoken Latin wore the words down over a thousand years, but the line is easy to follow: Ianuarius became enero, Martius became marzo, Aprilis became abril and Maius became mayo. The months of the year table shows the same Latin list behind French, Italian, Portuguese and many languages far beyond Europe.

Two months carry the names of men. Julio is the month of Julius Caesar and agosto that of the emperor Augustus; the Romans renamed the fifth and sixth months of their older year in their honour. Spanish turned the Latin initial I of Iulius and Iunius into the j of julio and junio, a sound written j but pronounced at the back of the throat.

The last four months still count. Septiembre, octubre, noviembre and diciembre are built on the Latin numbers seven, eight, nine and ten, a relic of a Roman year that began in March. When the start of the year moved to January the names stayed where they were, so the ninth month of the modern calendar is still called the seventh.

Lower case, gender and the setiembre question

Spanish spelling rules put the months in lower case. The Real Academia Española groups them with the days of the week and the seasons: a capital is used only when punctuation demands one, at the start of a text or after a full stop, or when the month is part of a proper name. The Revolución de Mayo, the uprising of May 1810 in Buenos Aires, is written with a capital because it is a name; en mayo and el 25 de mayo are not.

The months in Spanish are masculine nouns. They usually appear without an article (en enero, in January; enero es frío, January is cold), but the article comes back when an adjective or a clause narrows the month down: el enero pasado, last January, or el agosto en que se casaron, the August they married.

September has two accepted spellings. Septiembre keeps the p of Latin September; setiembre drops it, as many speakers do in pronunciation. The RAE accepts both forms, and setiembre is the usual spelling in Peru, Costa Rica and the Río de la Plata region according to Wiktionary's entry for the word. Septiembre is the form most style guides choose for formal writing, and it is the one used in this page's table.

How to write the date in Spanish

A Spanish date runs from small to large: day, month, year. The month stands between two instances of de, so 3 March 2026 is 3 de marzo de 2026, and with the weekday in front the full form is martes, 3 de marzo de 2026. The Unicode CLDR data that operating systems use for Spanish has exactly these patterns, plus the short numeric form 3/3/26 with the day first.

That day-first order matters when reading a numeric date. In Spain and Latin America, 4/7/2026 is the fourth of July, not the seventh of April; only some documents in the United States follow the English order. Years are written in figures without a point or space: 2026, not 2.026.

The first of the month has two spoken forms. According to the Diccionario panhispánico de dudas, the cardinal uno de enero is more usual in Spain, while the ordinal primero de enero is the more common choice in the Americas; every later day takes the cardinal, dos de enero, tres de enero. Both are written 1 de enero. For a range of months Spanish uses de … a or entre: de enero a marzo, entre mayo y julio.

Abbreviations of the months in Spanish

Software set to Spanish abbreviates the months as ene, feb, mar, abr, may, jun, jul, ago, sept, oct, nov and dic, the forms in the table. The single-letter set used on calendar headers and charts is E F M A M J J A S O N D. September is the only month with a four-letter abbreviation in this set; sep and set are also seen, the second matching the spelling setiembre.

In running text an abbreviated month takes a full stop and keeps its lower case, as in 3 ene. 2026. Where space allows, most Spanish style guides prefer the month written out in full.

Months and seasons north and south of the equator

The same twelve names describe opposite weather. In Spain and Mexico diciembre, enero and febrero are winter, el invierno; in Argentina, Chile and Uruguay those are the summer months, el verano, and Christmas falls in the heat. The four seasons, primavera, verano, otoño and invierno, follow the same lower-case rule as the months.

Some months carry holidays whose names are capitalised. Mexico's Día de Muertos falls on 1 and 2 November, and 12 October is marked across the Spanish-speaking world under different names, among them Fiesta Nacional de España in Spain and Día de la Hispanidad. In both cases only the holiday's name takes capitals; the month inside the date does not.