I've been seeing this a lot in the swedish speaking world, I believe it's the days between Christmas and New Years but I'm not sure if there's any celebration?? it seems like it's a big deal, please correct me if I'm wrong :^)
And by taking only a few days off, you can get a really long vacation. Dec 24, Dec 25, Dec 26, Dec 31, Jan 1 and Jan 6 are days were most people don't work, so a year like this when all red days are on weekdays you can easily be away from work long enough to forget your passwords :).
Btw, during the "mellandagarna" we wish people "God fortsättning!" (it comes between wishing them "God Jul!" and "Gott Nytt År!"). I am not joking.