This was the view from my living room window at 1am this morning. I battle to sleep in this weather even with an eye mask, blackout blinds OVER my Venetian blinds and curtains. Just that fact that I KNOW it is light outside bothers me. This is fairly dark as Sweden goes as Stockholm is pretty far South. Within the Arctic Circle things are much worse (or better, depending on how you look at it)
It is even worse for Muslims in Sweden, particularly in the north, during Ramadan. This year Ramadan goes from the 18th June to 17th July and Muslims have to fast between dawn and dusk. Which is pretty hard when there is no dawn or dusk. Last year Muslims in Iceland and Norway fasted for 22 hours during Ramadan.
Different Muslim communities have different ways of dealing with it. Some follow Mecca time when deciding times to fast. Others follow the dawn and dusk times for Southern Europe. Others follow the times there was last dawn and dusk where they live.
There is a movement at the moment to provide EU-wide rules for how Ramadan is observed in countries where it does not get dark.

