I say, and with God's success: The obligatory prayer, the prostration of recitation, and the funeral prayer are not valid during these three times: First: When the sun rises until it has risen and whitened to the extent of a spear or two. Second: When the sun is at its zenith until it passes. Third: When the sun turns yellow and weak - such that the eye can face it - until it sets, except for the afternoon of that day; for Al-Qabah bin Amer Al-Juhani, may Allah be pleased with him, said: "There are three times when the Messenger of Allah, peace be upon him, forbade us to pray in them or to bury our dead: when the sun rises until it has risen, when the sun is at its zenith until it tilts, and when the sun is close to setting until it sets," in Sahih Muslim 1: 568, Musnad Al-Mustakhraj 2: 424, Sahih Ibn Hibban 3: 348, Sunan Al-Tirmidhi 3: 348, and Sunan Abu Dawood 3: 208. And from Ibn Abbas, may Allah be pleased with them both, he said: "There were men who were pleasing to me, and the most pleasing of them to me was Umar, that the Prophet, peace be upon him, forbade prayer after dawn until the sun rises and after the afternoon until it sets," in Sahih Al-Bukhari 1: 211. As for voluntary prayers during these times, they are valid but disliked in a prohibitive sense. See: Maraqi Al-Falah, pp. 186-187, and Allah knows best.