Allah (Subhana Wa Ta’ala) has said in the Quran:
يَسْأَلُونَكَ عَنِ الْأَهِلَّةِ ۖ قُلْ هِيَ مَوَاقِيتُ لِلنَّاسِ وَالْحَجِّ
“They ask you (O Muhammad) about the crescent moons. Say: They are signs to mark fixed periods of time for mankind and for the pilgrimage.” Quran (2: 189)
Based on the Tafsir (commentary) of the above verse, the Fuqaha (Muslim Jurists) have stated that it is Fardh-alal Kifaya (communal obligation) to start the Islamic lunar months by sighting of the crescent moon. That means, if a group of Muslims fulfil the above obligation, then it will be sufficient for others in the community. However, if no ones fulfil this obligation, then the entire community will be sinful.
(Tafsir Mariful Quran, p.482)
The Prophet Muhammad (ﷺ) has said: “Do not fast unless you see the (crescent) moon, do not break your fast until you see the (crescent) moon.” (Sahi Al-Bukhari)
Therefore, even if a group of Muslims fulfil the above communal obligation, it is still a Sunnah of Prophet Muhammad (ﷺ) for all Muslims to carry out moon sighting to establish the Islamic lunar months.
Allah (Subhana Wa Ta’ala) has also said in the Quran:
إِنَّ عِدَّةَ الشُّهُورِ عِندَ اللَّـهِ اثْنَا عَشَرَ شَهْرًا
“Verily, the number of months with Allah is twelve months (in a year)” Quran (9:36)
Based on the above verse and the Sunnah of Prophet Muhammad (ﷺ), the Fuqaha have stated that moon sighting in all twelve months of the year are just as important as for the months of Ibadah (i.e. Ramadan, Shawwal and Dhul-Hijjah). Other Fiqh (Jurespudence) issues, such as calculations of Zakah (obligatory charity), Iddah (waiting period) for divorced women, ligitamacy of a child etc, are all dependent on the twelve lunar months.
It is Sunnah to look for the crescent moon on 29th day of each lunar months. If on the 29th lunar day, the crescent moon is not sighted locally and reliable/verified news has not been obtained from an foreign authority either, then the month will be completed as 30-days. It is not permissible to start the month on a doubtful day as stated below.
Ammar said: “Whoever fasts on a doubtful day has disobeyed Abul-Qasim (i.e. the Prophet Muhammad (ﷺ))”. (Sahih Al-Bukhari).
Whilst it is permissible to use scientific calculations to plan ahead when and where to sight the crescent moon, the Fuqaha have stated that it is not permissible to establish the month based purely on these calculations. In the commencement of every month, it is necessary to verify and validate the sighting of the crescent moon (Muhaqaq Ru’yat Basari).
Note that local moon sighting is the established Sunnah of Prophet Muhammad (ﷺ), as explained in the Muslim World League (MWL) meeting resolution by renowned Muslim Scholars from different parts of the world (Arabic/English). See also: Fatwa on Moon Sighting and Following Neighbouring Countries (Darul Uloom Deoband, India) [Urdu/اردو]
Checked by: Mufti Amjad Mohammed