The Duty of a Prisoner
Issue No. 1461- If a prisoner cannot ascertain the commence of the month of Ramadan, he should act according to his presumption, and fast in the month which is more likely to be the month of Ramadan. But if he can not presume any month to be the month of Ramadan, it will be in order if he observes fast on any month. However, if his imprisonment continues, he should as an obligatory precaution, observe fast in the same month next year.