In Sweden, we call public holidays “red days” in Sweden, so if you hear colleagues at work refer to “red days” or “röda dagar”, you now know what they are referring to.
Unlike in some other countries like New Zealand (where the author of this blog post is from), red days are lost if they fall in the weekend - you don’t get to redeem them the following Monday. This also explains why you may hear some peopler refer to years as “employer years”/“arbetsgivarår" or “employee years”/“arbetstagarår" - an employer year is where the red days fall in the weekend.
Here is a link which has the 2018 red days in Sweden (so you can now plan ahead and maximise your vacation time with “mellandagarna” - this is where you take vacation on a day that falls between a red day and a weekend. For example: National day is on June 6. This year is falls on a Wednesday, so you could take out the following Thursday and Friday as vacation days and have 5 days off in a row (Wednesday to Sunday) by only using up 2 vacation days.