In Sweden, during the winters, the nights are very long and daylight is for a couple of hours only; in summers it is vice versa. At the north pole daylight and darkness are for six months long each. At places such as the above how should one calculate the timings of prayers and fasting?
About all such circumstances, the Sharī'ah is silent and there is a need to do ijtihād. Muslims who are residing in such places should be told that this is something they must decide for themselves, whether individually or collectively.
A number of options can be adopted. For example, the time table of prayers and fasting of the nearest place can be adopted where the difference between dawn and dusk is not too pronounced. Another option is to adjust these timings according to the general routine of sleeping, getting up and going to work. Similarly, other courses can be taken.