How does one respond to the atheist's skepticism that God, in His legislations, ignored the prayer and fasting times for regions where the sun rises only once (a day) or where its daytime is extremely long, which suggests that He knows nothing about them?

Events and occurrences are ever-renewing, and the Sharia governs all of them. Its finite texts carry meanings whose implications are infinite, and the Prophet, peace be upon him, was given comprehensive speech. The fundamental principle in Sharia is that the Messenger, peace be upon him, clarified all that people need in their knowledge, sciences, and deeds, and that his message is comprehensive for all that the addressee needs concerning the fundamentals and branches of religion. The Sunnah is revelation, so it is incorrect to say that a legal ruling indicated by the Sunnah was not clarified by Allah. Scriptural texts vary in the clarity of their indications, and some issues require ijtihad (independent reasoning) in derivation, which is why Allah commanded us to ask the people of knowledge. In regions where the day or night is unusually long, the worship acts tied to the sun's movement – such as prayer and fasting – are to be estimated by analogy to the nearest lands where night and day are distinguishable and their combined duration is twenty-four hours, as mentioned in the hadith about the Dajjal and the estimation of prayers during his time.