In Tafsir Maarif ul Qur'an it is said that the Quran states that "(During Ramadan) eat and drink until the white thread of dawn appear to you distinct from its black thread." This results that fasting is a duty for Muslims only when days and nights are producing otherwise fasting is not necessary. So the Muslims of Svalbard have to fast only when days and nights are prominent by the sun. If Ramadan comes in June/December (when days and nights are not prominent by the sun in Svalbard, Norway) they may leave fasting and then complete their fasting in March/September (when days and nights are prominent by the sun in Svalbard, Norway). In Islamic law it is called Qadha. God says in the Quran: "God intends every facility for you; He does not want to put you to difficulties. (He wants you) to complete the prescribed period, and to glorify Him in that He has guided you; and perchance ye shall be grateful."