"Tuesday is a workday."
Translation:Tisdag är en vardag.
I don't see "workday" or "working day" necessarily being an exact synonym with "weekday" (in the way it excludes weekend), as one can work any day of the week between Mon-Sun and so called weekday might as well be one's day off from work.
- Vardag sure can mean workday or weekday (among other things), but there are also words "arbetsdag" for workday and "veckodag" for weekday (can mean any day of the week though).
- "Tisdag är en arbetsdag." is also an approved translation to the given english sentence.
"Vardag" is the opposite of "helgdag", where "vardag" normally means Monday - Friday and "helgdag" is Saturday - Sunday. (Christmas day, Boxing day and Good Friday etc are "helgdagar" too.)
"Arbetsdag" is a day when you work, so if you work in an office for example, "vardag" and "arbetsdag" coincide.