How do Muslims in Sweden fast when the sky remains white from sunset until dawn?

Fasting must be observed from the rise of dawn until sunset, as long as night and day alternate within 24 hours. The persistence of light after sunset does not matter; the criterion is the setting of the sun, as indicated by the action of the Prophet, peace and blessings be upon him. As for the 'Isha prayer, its time begins with the disappearance of the red twilight. If the twilight does not disappear until dawn, then the 'Isha prayer should be performed according to the timing of the nearest city where the twilight disappears.