Brother Munzzih of safeena.org wrote : :hmp1
Sighting the moon - the only correct way to knwo the begining of Ramadan
The obligation of fasting the month of Ramadan becomes incumbent upon the occurrence of one of two matters: to sight the crescent of Ramadan after the sunset of the 29th day of Sha^ban (the month directly preceding Ramadan) or, if the crescent is not seen, then completing 30 days of Sha^ban. So, the beginning of the month of Ramadan, as well as the end of the month is determined by sighting the crescent, and if not cited, then by completing the month with 30 days--as is the case with determining all the months of the lunar calendar. This is taken from the hadith of the Prophet related by al-Bukhariyy and Muslim
So, on the 29th day of Sha^ban, directly after the sun sets, the Muslims look towards the western horizon, and if the crescent (of the new moon) is seen, the following day will be the first day of Ramadan. If it is not seen, because of cloud cover or another reason, then the next day will complete 30 days of Sha^ban, and the day after that is the first day of Ramadan. The judge confirms the beginning of Ramadan if one upright Muslim, whose testimony is acceptable to the judge, bears witness that he saw the crescent. The conditions which must be met in a person for his testimony to be acceptable to the judge in this matter are several. He must be Muslim, male, pubescent, free, clear of enormous sins, clear of having his small sins exceed his acts of obedience, and one who abides by the ethics and manners of the people of his class. So if a person who did not satisfy these conditions testified to the judge that he saw the crescent, like, for example, a woman, or a child, or an enormous sinner, or a slave, the judge would not confirm the beginning of the month of Ramadan and announce to the general public to commence fasting--relying solely upon their testimony. However, if just one upright Muslim, who has the conditions listed above satisfied in him, testifies to the judge that he saw the crescent, the judge would confirm the beginning of Ramadan for the next day. This is for the hadith related by Abu Dawud from the route of ^Abdullah Ibn ^Umar who told the Prophet he had sighted the crescent and so the Prophet fasted the next day and ordered the others to fast as well.
Be warned of those who determine the month of Ramadan relying upon astronomical calculations. Prophet Muhammad informed us that such calculation is not relied upon in determining such matters. Imam Ahmad related in his Musnad that the Prophet said which means: <> Praise be to Allah, how easy the matter is. Any Muslim with a sound sight can observe the crescent. He does not need to rely on complex calculations only a few people understand.
