Having to regularly check which date is meant when a Swede gives you a week number can be frustrating, but there’s a method in this numerical merry-go-round.

Having to regularly check which date is meant when a Swede gives you a week number can be frustrating, but there’s a method in this numerical merry-go-round. “We’ve scheduled the meeting for week 42 as the project should be near completion by then.” If you’ve ever read (or heard) a sentence like any of the above in Sweden and found yourself cursing in frustration and clutching your phone while you google “what date is week 23?”, you are not alone. The use of week numbers to refer to points in time – either in the past or future, but usually within the current year or beginning of the next one – is common in some European countries, and Sweden has embraced it since it was introduced in the 1970s. Sweden isn’t alone in this practice and its Scandinavian neighbours Denmark and Norway also use numbered weeks to refer to dates. In Anglophone countries, including the United Kingdom and United States, the convention is not used, and weeks are more likely to be referred to loosely as the “second week in July”. If a specific week needs to be given, it might be written down as a range of dates or something like “the week commencing Monday, July 20th”. As such, the use of week numbers can be very jarring to people not used to them because they are difficult to connect to an actual date and therefore don’t seem to give any kind of useful reference point. They require the extra step of referring to a calendar to look up a date which could have just been given in the first place. At the same time, Swedes often seem to instinctively be aware of the week number they’re currently in, the exact date of an earlier week number, and how far into the future a given week number might be.