det jeg har hørt, og som virker logisk, uten å kunne si at det er et fasit svar, er at de som bor i de områdene der solen ikke går ned under ramadan måneden, skal faste efter det landet som ligger nærmest, der solen faktisk går ned.
Kilde: http://islamqa.info/en/ref/5842/fasting%20sun
''So the Muslims in the country mentioned in the question have to define the times of prayer in that land, basing those times on the closest country in which the night and day can be distinguished from one another and the times of the five daily prayers are known according to the signs described in sharee’ah, within each twenty-four hour period. ''