Irish · Gaeilge · Latin script
Days of the week in Irish: Dé Luain to Dé Domhnaigh, the three fasts
The days of the week in Irish are Dé Luain, Dé Máirt, Dé Céadaoin, Déardaoin, Dé hAoine, Dé Sathairn and Dé Domhnaigh. Each one also has a second form with the article, an Luan or an Aoine, and three of the seven are named after the Christian fast.
The days of the week in Irish, Monday first
The first form is the one used for on that day, as in glaoigh orm Dé Luain, ring me on Monday. The second, under it, is the noun with the article, as in inniu an Luan, today is Monday. Both forms and both examples are the entries of foclóir.ie, the New English–Irish Dictionary.
| English | Irish (on …) · noun | Note |
|---|---|---|
| Monday | Dé Luainan Luan | Latin dies Lunae, the Moon |
| Tuesday | Dé Máirtan Mháirt | Latin dies Martis; feminine, so the article lenites it |
| Wednesday | Dé Céadaoinan Chéadaoin | céad aoine, the first fast of the week |
| Thursday | Déardaoinan Déardaoin | the day between the two fasts; written as one word |
| Friday | Dé hAoinean Aoine | aoine, fast: the day of the fast |
| Saturday | Dé Sathairnan Satharn | Latin dies Saturni |
| Sunday | Dé Domhnaighan Domhnach | Latin dies Dominicus, the Lord's day |
Origins as given in the Wikipedia article on the Irish calendar and in Wiktionary: Céadaoin from Old Irish céd aín, first fast; Déardaoin from eter dá aín, between two fasts; Aoine from aíne, fast.
Four Roman days and three fasting days
The days of the week in Irish mix two traditions. Four days took their names from Latin, the language of the Church that brought writing to Ireland: Luan from dies Lunae, Máirt from dies Martis, Satharn from dies Saturni and Domhnach from dies Dominicus, the Lord's day that replaced the day of the Sun. English kept the Sun and Saturn; Irish kept Saturn and the Lord.
The three days in the middle of the week come from monastic practice. The Wikipedia article on the Irish calendar derives Céadaoin from Old Irish céd aín, the first fast, Aoine from aíne, fast, and Déardaoin from eter dá aín, between the two fasts. Wednesday and Friday were days of fasting, and Thursday is literally the day in between. Wiktionary adds that Aoine reflects the Catholic custom of fasting and abstaining from meat on Fridays.
Scottish Gaelic and Manx kept the same three fasts. The days of the week in many languages table gives Scottish Gaelic Diciadain, Diardaoin and Dihaoine and Manx Jecrean, Jerdein and Jeheiney beside Irish Céadaoin, Déardaoin and Aoine, while Welsh and Breton, the Brittonic branch, use the Roman planets for those days. The Celtic word list compares the languages word by word.
Dé Luain or an Luan: which form to use
Each of the days of the week in Irish has two forms, and the choice depends on the job the word does in the sentence. The form with Dé answers the question when: glaoigh orm Dé Luain, ring me on Monday; maidin Dé hAoine, Friday morning. Dé here is an old word for day, and the name after it is in the genitive: hence Sathairn and Domhnaigh beside Satharn and Domhnach.
The form with the article names the day as a thing. Inniu an Luan means today is Monday, and bíonn sé dúnta ar an Luan means it is closed on Mondays, every Monday. A range uses the bare name: Luan go hAoine, Monday to Friday. All of these phrases are examples from foclóir.ie.
Thursday breaks the pattern. Déardaoin already contains the Dé, fused into one word, so foclóir.ie writes glaoigh orm Déardaoin with nothing in front. With the article it is an Déardaoin.
Capitals, fadas and the h in Dé hAoine
Irish writes the days of the week with a capital letter in both forms: Dé Máirt, an Mháirt. The fada, the acute accent on á, é, í, ó and ú, is part of the spelling and marks a long vowel, as in the á of Máirt. A name written without its fada is misspelt in Irish, not merely simplified.
Two of the noun forms change their first letter. Máirt and Céadaoin are feminine, and the Irish article lenites a feminine noun, so the dictionary headwords are an Mháirt and an Chéadaoin, with an h after the first consonant. The masculine days, an Luan, an Satharn, an Domhnach, stay as they are.
Friday shows a third change. Before the vowel of Aoine, Dé adds an h, and Irish writes such a prefixed letter in lower case even in front of a capital: Dé hAoine. The same h appears in Luan go hAoine.
| Irish | English |
|---|---|
| Inniu an Luan. | Today is Monday. |
| Glaoigh orm Dé Céadaoin. | Ring me on Wednesday. |
| Bíonn sé dúnta ar an Aoine. | It is closed on Fridays. |
| Luan go hAoine | Monday to Friday |
| Dé Luain an 10 Iúil | Monday 10 July |
| maidin Dé Luain, maidin Luain | Monday morning |
| tuirse an Luain | that Monday-morning feeling |
All examples from foclóir.ie, the New English–Irish Dictionary of Foras na Gaeilge.
The standard and the dialects
The spellings on this page are those of An Caighdeán Oifigiúil, the official standard for written Irish. It was first published in 1958, revised in 2017, and is kept by the translation service of the Houses of the Oireachtas, which opened a statutory review with a public consultation in March 2026. Dictionaries such as foclóir.ie follow it.
Spoken Irish has three main dialects, Munster, Connacht and Ulster, and they differ in sound more than in these names. Wiktionary records separate pronunciations for each dialect for many of the words, and that is why no single IPA transcription is given in the table. Learners who follow a course should take the pronunciation from the dialect of the course.
Older books printed in the Gaelic type, the cló Gaelach, mark lenition with a dot over the letter, so an Mháirt appears there as an Ṁáirt. The Irish uncial font specimen shows that type in use.
Questions about the Irish days of the week
What are the days of the week in Irish?
Dé Luain (Monday), Dé Máirt (Tuesday), Dé Céadaoin (Wednesday), Déardaoin (Thursday), Dé hAoine (Friday), Dé Sathairn (Saturday) and Dé Domhnaigh (Sunday). With the article they are an Luan, an Mháirt, an Chéadaoin, an Déardaoin, an Aoine, an Satharn and an Domhnach.
When do you use Dé in the days of the week in Irish?
When the day says when something happens: Dé Luain, on Monday. To name the day itself, use the article: inniu an Luan, today is Monday.
Why does Thursday have no Dé?
Because the Dé is already inside the word. Déardaoin is written as one word, so on Thursday is simply Déardaoin.
What do Céadaoin and Aoine mean?
Céadaoin means the first fast and Aoine the fast. Déardaoin, Thursday, is the day between the two fasts.
Are Irish day names capitalized?
Yes, in both forms: Dé Luain and an Luan.