Wiktionary says this about workday: Any of the days of a week on which work is done. The five workdays in many countries are usually Monday to Friday (and are defined as such in official and legal usage even though many people work on weekends). and this about weekday: A weekday is any day of the week except Sunday and often also Saturday. "Weekday" usually means the same as workday, however in some countries with a five-day workweek, the term weekday may still retain the old meaning "all days except Sunday", from when most people worked on Saturdays.
tl;dr Basically yes, though there may be exceptions in some cases.
In Swedish, en vardag is any day that is not a Saturday, Sunday, or public holiday.
A Swedish acquaintance once insisted I had to pronounce "är" as "ä", dropping the "r". I was confused because when I first learned the word on DuoLingo, I did hear the R sound, and I'm practically sure I also heard it in a show, once, on which one of the characters (and actor) was Swedish (the show was American). So my question is: how common is it to drop the R sound in "är"?
It's usually dropped, especially before consonants, but not always. Sometimes it pops up even in contexts where it's usually swallowed. The d at the end of vad is also usually swallowed, so the most natural way of saying this sentence would be like "Vaeenvarda" (the g at the end of dag is also usually omitted).
Thank you! Another question if you don't mind: you mention the [ r ] sound is dropped in 'är' most of the time, especially before consonnants... does that mean that it will be pronounced more often before a vowel or is that still not too common? And is pronouncing these letters (the [ r ], the [ g ], etc.) a little too strange in natural speech or is it acceptable? (I'm thinking of the second T in 'twenty' which can be swallowed, but won't come off as strange if pronounced, for instance...)