"On Monday to Friday."
Translation:Dé Luain go Dé hAoine.
The 'i' is because Dé is followed by the genitive case.
Luan = nominative case, e.g. an Luan
Luain = genitive case, e.g. Dé Luain.
Luanta = Mondays
From Monday to Friday, Ó Luan go hAoine seems more natural in both languages.
Maybe slightly off topic, but I do not quite get the meaning of the English phrase. "On monday" to me implies something happening on that single day, whereas "to friday" refers to a period of time up to that day. Having both in a single phrase confuses me? Yes, something can start on one day and then last up to another day, but then I would have expected "from...to"? Is this an idiom I have not come across in the past or what am i missing?
Would "An Luan go an Aoine" be correct and equivalent? I was trying to figure out the difference, and I read an article that said "An weekday" indicated a habitual occurrence whereas "Dé weekday" meant a specific day.
No, it wouldn't be correct or equivalent. ar an Luan, with the reposition ar, generally indicates a habitual occurrence, though it can also be used to refer to a specific Monday. You would also need to use go dtí before an. Indeed, you could probably make a strong case for go dtí instead of go in this exercise too - Dé Luain go dtí Dé hAoine.