It has already been indicated that the period of obligatory Fasting is the month of Ramadan. The daily period of observance starts before the break of the dawn and ends immediately after sunset. Normally there are accurate calendars to tell the exact time, but in the absence of such facilities on should consult one’s watch and the sun’s position together with the local newspapers, weather bureau, etc.
The Fasting of Ramadan is obligatory on every responsible and fit Muslim (Mukallaf). But there are other times when it is strongly recommended, after the Traditions of Prophet Muhammad. Among these times are Mondays and Thursdays of every week, a few days of each month in the two months heralding the coming of Ramadan, i.e., Rajab and Sha’ban, six days after Ramadan following the ‘Eed-l-Fitr Day. Besides, it is always compensating to fast any day of any month of the year, except the ‘Eed Days and Fridays when no Muslim should fast. However, we may repeat that the only obligatory Fasting is that of Ramadan – which may be 29 or 30 days, depending on the moon’s positions. This is a pillar of Islam, and any failure to observe it without reasonable excuses is a severely punishable sin.
Knowing what Fasting can do for man, God has enjoined, as an alternative, the fast of three days on anyone who breaks an oath. Similarly, if someone declares his wife as forbidden for him as his mother, - an old pre-Islamic custom, he must pay for his carelessness and irresponsibility. To expiate for this sin he has, as an alternative, to observe the fast of two consecutive months (Qur’an, 2:183-185; 5:92; 58:1-4). [It is interesting to note that expiation for breaking an earnest oath is the feeding, or clothing of ten indigent persons. If that is not possible the offender must emancipate a slave or ransom his freedom. If that also is not possible then the fasting of three days is the last resort (Qur’an, 5:92). In the case of that thoughtless use of words, that distasteful pre-Islamic custom, the offender’s first obligation is to emancipate a slave or ransom his freedom. If he cannot afford that, then must observe the fast of two consecutive months before he resumes intimacy with his wife. If he cannot fast, then he must feed sixty needy person or distribute sixty average meals among the poor. There are other occasions where fasting is either required or recommended to substitute for unmanageable tasks (Qur’an, 58:1-4; cf – 2:196)].