I don't think so, what they usually say in Swedish books about etymology is that it comes from the word löga, an old word for 'wash'.
It becomes even more obvious when you see the Icelandic and Faeroese counterparts laugardagur and leygardagur.
Oh well, at least I'll remember it well! "Wash day" makes a lot of sense as well. Tack!
So what about "söndag"? I find two different explanations on the net, seventh day or, as in English, the day of the sun. Does anyone know?
Söndag<Sunnudagr, Old Norse version of dies Solis, or the day of the sun. It is only the seventh day of the week since 1972. Saturday in German is Samstag, which is a shortening of sambaztag, which is the Germanic rendering of Sabbath day, which is from Hebrew and refers to the seventh day of the week.
Is it an audio glitch that I hear the g clearly on sondag but not lörsdag (sorry for mis-spelling, but it doesn't show when I comment.)
I hear it on both. But in real life, we usually don't say the g sound here, only if we're speaking extra clearly. It usually sounds as though it were written Lörda å sönda
Yes, helgen or helga = the weekend, en helg = a weekend. It's related to the word "holy" and thus "holiday".
We don't say helga in Swedish for the weekend, that's probably Norwegian. We only say helgen (en helg in the singular).
weekend is sometimes used in Swedish when speaking about holidays, trips etc, like en weekendresa 'a weekend trip', but not in ordinary sentences like Vad ska du göra i/till helgen? ('What are you doing this weekend?')
There are also the words veckoslut and veckända, but both of them are used more in Finland than in Sweden afaik.
Rarely, mostly in the south I think. It's used in Denmark, which is why I assume it's a southern Swedish thing, though I'm not from there (only visited).