In some regions in proximity to the North Pole, e.g. Norway, the times in relation to the rest of the world are abnormal. Some days after sunset and even before disappearance of shufuq abyadh (the whitish glow in the western horizon after the redish glow), the sun rises. Thus, the time of Isha does not set in. In some regions the sun remains above the horizon for six months, and in some places it is night for six months.
The classical Fuqaha had discussed and elaborated on this issue. According to one group of Fuqaha, Isha and all other Salaat remain obligatory and have to be performed in view of the command of five Fardh Salaat daily, which is substantiated by the Sunnah.
The Sunnah has not excluded any land from this obligation. These Fuqaha base their ruling on the Hadith which says that during the era of Dajjal there will be a day the equivalent of one year. It will be a long day. The Sahaabah queried the performance of Salaat on that day. Will only five Salat be performed in that marathon day of a year? Rasulullah (sallallahu alayhi wasallam) explained that the times of Salaat will be calculated. That is: Five Salaat for every 24 hours.
According to the other Fuqaha, the five Salaat are conditional with their five specific times. If the incidence of a specific Salaat time does not develop in a region, then that particular Salaat is waived. They present the analogy of Wudhu which has Four Fardh acts according to the Hanafi Math-hab. If both feet have been amputated, the fardh of washing the feet falls away. Similarly, the Fardh Salaat will be waived if its time does not develop in many regions.
Regarding the Hadith pertaining to the era of Dajjaal, these Fuqaha are of the opinion that since it is in conflict with Qiyaas (Analogical Reason), it may not be presented as a basis for a ruling. In terms of the Usool of Fiqh, the Khilaaf-e-Qiyaas narration shall be confined to its original purpose and not be used as a basis for extrapolation for extending the ruling to another issue.
Shaikh Akbar Muhayyuddeen Ibn Arabi (rahmatullah alayh) has elucidated this issue in his Futuhaat. According to him, the event of the long day during the era of Dajjaal will in reality not be one year literally. The times of Salaat will be normal. However, due to the deception of Dajjaal people will not observe the movement of the sun, sunrise and sunset. The people will perceive this day to be as long as a year.