Moonsighting or Calculations

According to some people calculations should be used to determine the beginning and ending of the Islamic lunar months, in the same manner that calculations are used to determine the timings of prayers, so that ease is ensured, and differences among groups regarding the sighting of the crescent are prevented.

However, it must be explained here that Shariah has standardized the timings of prayers on the conditions of the Sun, that is, the time for a specific prayer will start or end when the Sun is in a specific position or condition. Besides that, Shariah has not defined any specific method by which the position or condition of the Sun must be ascertained, that is, by looking at the Sun or by any other means. Allah (SWT) says: ((أَقِمِ الصَّلَاةَ لِدُلُوكِ الشَّمْسِ إِلَىٰ غَسَقِ اللَّيْلِ)) meaning “Establish Prayer from the declining of the Sun to the darkness of the night” (Al-Quran 17:78)

Thus, neither has the Shariah limited the ascertaining of the conditions of the Sun to any specific method, nor has it forbidden the use of calculations in determining the timings of prayers. Thus, any method that produces preponderance of evidence (ghalabat al-zann), that the Sun is in such a condition that the time for such and such prayer has started, can be adopted, even if it is a calendar of the timings of the prayer made by the use of calculations. This is because with respect to the commands of Shariah, a Muslim is obliged to follow the preponderance of evidence (ghalabat al-zann), and the conditions of the Sun can be sufficiently ascertained through the use of calculations.

In contrast, the Shariah has explicitly restricted the matter of the crescent to its sighting. This is clear in the first evidence that has been mentioned for the first stance, which is that Abdullah ibn Umar رضی اللہ عنہ narrated that Rasool Allah ﷺ mentioned Ramadan and said: ((لَا تَصُومُوا حَتَّى تَرَوْا الْهِلَالَ وَلَا تُفْطِرُوا حَتَّى تَرَوْهُ ، فَإِنْ غُمَّ عَلَيْكُمْ فَاقْدُرُوا لَه)) meaning “Do not fast unless you see the crescent (of Ramadan), and do not give up fasting till you see the crescent (of Shawwal), but if the sky is overcast (if you cannot see it), then act on estimation (i.e. count Sha'ban as 30 days).” [Al Muwatta H:317-318; Bukhari H:1906-1907; Muslim H:2498]

And not only did the Shariah restrict the determining of the crescent to its sighting, but explicitly forbade the use of calculations in this matter. Thus, Imam Bukhari included a chapter "لا نکتب ولا نحسب” meaning “Neither do we write, nor do we calculate” in his Book of Fasting, and narrated from Abdullah ibn Umar رضی اللہ عنہ that the Rasool Allahﷺ said: ((إِنَّا أُمَّةٌ أُمِّيَّةٌ ، لَا نَكْتُبُ وَلَا نَحْسُبُ الشَّهْرُ هَكَذَا ، وَهَكَذَا يَعْنِي مَرَّةً تِسْعَةً وَعِشْرِينَ ، وَمَرَّةً ثَلَاثِينَ)) meaning "We are an illiterate nation; we neither write, nor know accounts. The month is like this and this, i.e. sometimes of 29 days and sometimes of thirty days." [Bukhari H:1913; Muslim H:2511; Abu Dawood H:2319; Nisai H:2140]

It cannot be said here that the word unlettered (ummiyah) describes the condition of the Muslims at that time, that they did not have the knowledge of calculations, because the Muslims were obligated to follow commands, such as Zakat, Ushr and the distribution of inheritance, which could not be fulfilled without the knowledge of calculations. Rather the purpose of referring to the Ummah as unlettered is to make it evident that if the crescent is not sighted on the 29^th day, the month should simply be completed after thirty days, instead of subjecting this process to the complexities of calculations and trying to determine whether the crescent would have appeared or not. So, these words إِنَّا أُمَّةٌ أُمِّيَّةٌ, لا نکتب ولا نحسب are used in the style of rhetoric (بلاغت) to emphasize that calculations should not be used in determining the start of the lunar months. Thus, the matter in which calculations must not be used is the specific issue of the sighting of the crescent. Hence, on the one hand an explicit command has been given to use the sighting of the crescent to determine the start of the lunar month, and on the other hand it has also been forbidden to use calculations for this matter.

Thus, it is understood that there is a clear difference between the nature of the command of determining the timings of prayers and the nature of the command of determining the start of the lunar month.  From the jurisprudential point of view this difference can be explained by understanding that the cause (sabab) for the start of the lunar month is the sighting of the crescent, not any specific condition or position of the crescent, whereas the cause (sabab) of the beginning of the time of a prayer is the specific condition of the Sun, not the sighting of the Sun. Thus, the nature of the causes (asbaab) are different for both commands, and they are not similar.