Sa’ad ibn Abdillah, from Hamzah ibn Yala, from al-Barqi, from Ubayd ibn al-Husayn, from Abdillah ibn Sinan, from Abu Abdillah عليه السلام, peace be upon him: Imam عليه السلام said: “As for voluntary fasting, you may break your fast between yourself and the night whenever you wish. And as for the fasting of making up an obligatory fast, you may break your fast until the decline of the sun (zawal al-shams). Then when the sun has declined, you do not have the right to break your fast.”