Fasting: Can the Full Moon Indicate the Start Date of Ramadan for Qadā’ Purposes?

Practical Laws of Islam as per the teachings of Imam Khamenei

Fasting: Can the Full Moon Indicate the Start Date of Ramadan for Qadā’ Purposes?

English:

Question #842:

Can the night of the full moon, which is the fourteenth night of the month, be taken as a reliable basis for calculating the first day of the month so as to determine whether the Day of Doubt was the thirtieth of Ramadan and to apply its rule, for example, so that all who did not fast on that day may have evidence concerning the necessity to perform qaḍā’ for the thirtieth day of Ramadan and whoever fasted that day, considering Ramadan to continue, may know that he is free of obligation?

Answer #842:

That which has been mentioned does not constitute shar‘ī evidence for anything mentioned. However, if it brings knowledge to the mukallaf his obligation is to act in accordance with his knowledge.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Fasting