What better way to begin the week than with a rundown of the names of the days in Icelandic? As in English, they all end in the equivalent of “day” – dagur. So you only need to know the declension of one word in order to work with all seven. Note that the days of the week are not capitalized in Icelandic as they are in English, other than at the beginning of a sentence. Let’s take a look at them and learn some basic expressions related to the word for “day”.

The days of the week in Icelandic are as follows:

Dagarnir í vikunni – Days of the Week
Sunday sunnudagur
Monday mánudagur
Tuesday þriðjudagur
Wednesday miðvikudagur
Thursday fimmtudagur
Friday föstudagur
Saturday laugardagur

The common element as mentioned is the ending -dagur:

dag/ur (m) – day
singular plural
nom dagur dagar
acc dag daga
dat degi dögum
gen dags daga

To talk about what day it is, the following expressions are useful:
í dag – today
í gær – yesterday
á morgun – tomorrow

Hvaða dagur er í dag? – What day is today?

Í dag er mánudagur. – Today is Monday.
Í gær var sunnudagur. – Yesterday was Sunday.
Á morgun er þriðjudagur. – Tomorrow is Tuesday.

Just these three expressions can be used as a drill to learn the days of the week, just cycle through each day as “today”.

When you want to talk about something happening on a particular day or days, there are a couple different ways to do it depending on what you are trying to express. For a specific day you would use á + accusative singular with the definite article:

Við förum til Íslands á föstudaginn. – We are going to Iceland on Friday.

If you are talking about something you do habitually or repeatedly on certain days, you use á + dative plural:

Hún fer í sund á þriðjudögum. – She goes swimming on Tuesdays.

If you want to emphasize the idea of “every”, the expression
á hverjum degi – every day
is used. Here we see day in the dative singular.

Á hverjum mánudegi ég fer í bío. – I go to the movies every Monday.

Some other expressions with dagur:

dagsins” – of the day, as in súpa dagsins – soup of the day. This is just the genitive singular form.
nú á dögum – nowadays
dag frá degi – from day to day / day after day
í fyrradag – the day before yesterday
daglega – daily