(9) 斋月的开始，以看见新月为确定，或以沙尔邦月满三十天为确定。凡亲眼看见新月之纤月，或从可靠的人那里听闻此事者，都有义务封斋。

(9) The onset of Ramadaan is confirmed by the sighting of the new moon, or by the completion of thirty days of Sha’baan. Whoever sees the crescent of the new moon or hears about it from a trustworthy source is obliged to fast.

使用天文计算来确定斋月的开始是一种bid'ah（创新），因为先知（愿安拉的慈悯与祝福降于他）的圣训明确说道："你们见到新月就开始斋戒，见到新月就停止斋戒。"如果一位成年、神志清醒、诚实可靠、视力良好的穆斯林说他亲眼见到了新月，那么我们就应当相信他的话，并据此行事（即开始斋戒）。ﷺ

Using calculations to determine the onset of Ramadaan is bid’ah, because the hadeeth of the Prophet (peace and blessings of Allaah be upon him) clearly states: “Fast when you see it (the new moon) and break your fast when you see it.” If an adult, sane, trustworthy, reliable Muslim who has good eyesight says that he has seen the crescent with his own eyes, then we should take his word for it and act accordingly (i.e., start fasting).