How to Use the Days of the Week in Spanish

Spanish days of the week are not capitalised in the middle of a sentence. This is one of the most common errors English speakers make, because English always capitalises Monday, Tuesday, etc.

The only time a day of the week is capitalised in Spanish is when it begins a sentence:

This is consistent with how Spanish treats months, nationalities, and languages -- all lowercase mid-sentence, all capitalised when starting a sentence.

All seven days of the week in Spanish are masculine. There are no exceptions. This means you always use el (singular) or los (plural), never la or las.

When you use an adjective with a day, it must agree in gender: un buen lunes (a good Monday), los domingos tranquilos (peaceful Sundays). Always masculine.

Use ser when stating what day it is as a fact of identity. This is by far the most common construction:

Some Spanish speakers in Spain use estar in the construction “estamos a + day” to indicate the current calendar position:

This “estamos a” construction is more common in Spain than in Latin America. In Latin American Spanish, “hoy es” is the dominant form. Both are correct; in conversation, “hoy es lunes” will be understood everywhere.