Not to be completely sure, but I think the direct translation of 'weekday' is 'giorno feriale'.
If not correct, please correct me.
Tuesday is one day of the week. Why is that wrong? Now i lost one heart :(
Nobody talks like this in English. It might have been possible if there were like two Mondays, three Wednesdays, but only one Tuesday in a week. Usually just "a" or "an" are used. In Italian there are no separate words for "a/an" and "one', so in both cases they use "un/uno/un'/una".
Who doesn't talk like this in English? "Tuesday is one day of the week; Wednesday is another." Bingo!
If I were to say "one day" it is "un giorno." I would report it. If this happened to you on a Tuesday, then that is one day of the week I wouldn't want to be in your shoes. ;)