What are the recommended days for voluntary fasting during the month and week, and what is the correct time for Iftar and Suhoor?

Allah has legislated supererogatory acts of worship (Nawafil) for His servants to draw closer to Him. These are of two types: absolute, such as fasting one day and breaking fast the next, and restricted. The restricted type, in turn, is divided into that restricted by the person's situation, such as the fasting of an unmarried youth, and that restricted by a specific time, which is generally better. The fasting restricted by a specific time includes fasting on Mondays and Thursdays, three days of each month (especially the white days), the day of Ashura (with a day before or after it), and the day of Arafah for non-pilgrims. As for periods, it is Sunnah to fast six days of Shawwal, and to increase fasting in Muharram and Sha'ban. Fasting in the path of Allah distances one's face from Hell for seventy years. Fasting begins from the dawn and ends at sunset, and it is recommended to delay the Suhoor (pre-dawn meal).