Moon Sighting Is Obsolete: Lunar Month Starts Should Be By Astronomical Conjunction

For this year's Eid Al-Fitr 1440 A.H. (2019 C.E.), the Muslim world had some countries, as well as some masjids in the West, ending the Ramadan fast on Tuesday. In Kitchener/Waterloo, we had the Kitchener mosque, following astronomical calculations, end the fast on Monday, while the Waterloo Masjid, following sighting, ended it on Tuesday.

Seeing the Unseeable

The problem here is that it was astronomically impossible to sight the new moon on Monday, since it is not illuminated at all.

Here is Monday June 3rd at sunset, in Riyadh Saudi Arabia. The moon's altitude is 0d33' (~ 0.6 degree) above the horizon, is too close to the sun to be seen, and there is no crescent to be seen (illumination is only 0.1%). One degree is approximately your pinky finger's width, when your hand is fully extended!

And here is Tuesday June 4th at sunset. Now the illuminated fraction is 1.7% (you can see a faint crescent) and it is 12d36' above the horizon, and it is considerably moved away from the sun, as it does every day.

You can verify this data for yourself by downloading Stellarium, a free planetarium software. There are also several phone apps, including Lunar Phase for Android.

A Saudi astronomer stated the obvious, that the moon could not be seen on Monday.

Despite all this, the crescent moon was sighted magically by people with supposed superman vision, in Saudi Arabia, and the Saudi courts blindly took it as fact, declaring that Eid is on Tuesday!

The debate about when a lunar month starts in the Islamic calendar is an old and recurring one. It has happened several times during the last several decades, early in the 20th century, and even back in the 1300's C.E, as I will detail below.

Politics and sectarianism also plays a role: in the same country, the Shia and Sunni sects would have Eid on different days intentionally. Even the BBC chronicled such a divide this year in Iraq, Yemen, and elsewhere.

Here are some quotes from the book الادلة في اثبات الاهلة by Taqi Al-Din Al-Subki, a renown Shafii scholar who died in 1355 C.E.

The booklet was published by Samira Dawood Al-Ani, in a critical edition, and can be downloaded from here.

The reason he wrote this booklet is that in 1348 C.E. (= 748 A.H., that is 671 years ago!) when the crescent of Dhul Hijjah, the last month of the Hijri year was being sighted, it could not be seen according to astronomers, and was not seen in the Levant or Egypt, yet some people claimed they have seen it. As a judge, he refused to declare that the moon was sighted, and that the following day is end of Dhu Al-Qe'da.

سبب كتابة هذه الدراسة
ص 95
فقد وقع في هذا الشهر و هو ذي الحجة سنة ثمان و اربعين و سبع مئة مسألة تحتاج الى النظر فيها ... و الذي وقع انه تراءى الناس الهلال ليلة الاحد فلم يروه مع كثرتهم و طلوعهم على المنارة في دمشق، و اخبر جماعة ممن يوثق بمعرفتهم: بان رؤيته تلك الليلة غير ممكنة في العادة، فلما كان في ثامن يوم جاء اثنان او اكثر قليلا شهدوا برؤيته ليلة الاحد و هم ليسو بارزي العدالة، لكن زُكوا مع اطباق البلاد - مصر و غزة و القدس و سائر الشام و طرابلس و صفد و حمص و بعلبك و حماة - على انهم لم يروه الا ليلة الاثنين، و اخبر جماعة ممن رآه ليلة الاثنين انه لم يمكث كثيرا و غاب قبل العشاء من ليلة الاثنين

ص 150
كان الداعي الى كتابة هذه الكراسة تكرار امثال هذه الواقعة في سنين كثيرة و فحشت في هذه السنة جدا فامتنعت من تنفيذها ثم جاء الخبر من الديار المصرية و جميع البلاد الشامية بانهم عيدوا خلاف ما عيدوا في دمشق ... ذي الحجة سنة ثمان و اربعين و سبع مائة بالعادلية بدمشق

Although he uses the traditional method of actual sighting of the crescent, he also recommends that a judge learn the limitations on the sighting of the crescent moon for himself, rather than relying on others to advise him.

ص 118
فصل
من المقدمات التي يحتاج الى معرفتها: تسيير منازل الشمس و القمر و قربه و بعده منها و قدر ارتفاعه عن الافق و قدر النور في جرمه و قدر مكثه بعد غيبوبة الشمس الى ان يغيب و يسمى كل واحد من هذه الثلاثة قوسا، و قالوا: اذا كان قوس الرؤية ست درج و قوس النور تسع درج و قوس المكث تسع درج امتنعت رؤيته، و ان زاد كل من الثلاثة درجة امكن بعسر، و كذلك اذا زاد اثنان دون الثالث، و كلما حصلت الزيادة قوي الامكان و يحتاج ايضا الى النظر في صفاء الجو و كدرته و كون الهلال من جهة الشمال او الجنوب و اختلاف مطالعه و مطالع البروج و مغاربها، و الاولى للقاضي ان يمارس ذلك ليعرفه من غير تقليد، فإن لم يعرف قلد من يعرفه

And imposes some limits that if astronomers say that the crescent could not be sighted, then any testimony claiming that it was has to be rejected, contrary to what Saudi Arabian courts did 2 days ago. Moreover,

ص 105
فصل
من اقوى الاسباب الموجبة للريبة: اخبار من يوثق به علما و دينا من اهل الحساب و علم الهيئة: ان الهلال لا يُرى، و من مارس هذا العلم عرف ان اهله يدركون ذلك لا محالة، غير انه على مراتب:
منها ما يقطع فيه باستحالة الرؤية
و منها ما يحتمل الرؤية احتمالا بعيدا
و منها ما يحتمل احتمالا قريبا
و منها ما يكون امكان الرؤية فيه راجحا
و منها ما يكون الامكان جليا واضحا
و نعني الاستحالة هنا: الاستحالة العادية لان الامكان العقلي موجود، و انما المستحيل عادة كالمستحيل عقلا في ذلك، و متى حُكم باستحالة الرؤية امتنع قبول الشهادة بها

And also quotes astronomers with the length of the lunar year, and that it either has 7 months of 30 days and 5 months of 29 days, or 6 months of each. So, if a year already has 7 months of 30 days, the 8th and subsequent months could not be anything other than 29 days each, and any testimony of sighting contrary to this has to be rejected.

ص 149
السنة القمرية ثلاث مئة و اربعة و خمسون يوما و خمس و سدس، و بمقتضى هذا يكون في كل سنة سبعة كوامل و خمسة نواقص او ستة كوامل و ستة نواقص، فلا تزيد الكوامل على سبعة، فلو اكملنا سبعة اشهر في السنة ثم غم علينا في الثامن، ان اكملناه خالفنا الحساب (هذا امر مقطوع به في علم الهيئة و ليس في الشرع ما يرده)، و قد لا يجسر الفقيه يحكم بالنقص لا سيما اذا لم يكن عنده حساب خاص بل مجرد هذه القاعدة و تقدم اكمال تلك الشهور، و لكن هذا فرض نادر فلذلك ما اشتغال فقهاء به

Lunar Months Should Be Calculated Only and By Conjunction

Now that we have shown that Eid Al-Fitr for 1440/2019 was wrong in many countries, I like to go further and avoid the reason for all this dilemma: sighting should be obsolete, specially in this day and age of technology. Astronomical calculations should be the sole method for determining the start of lunar months.

This will not only avoid the above dilemmas, but also allow for a predictable calendar to be published in advance.

And I am not making this stuff up ...

More than 80 years ago, an Egyptian scholar, and judge, Ahmed Shaker, wrote a short booklet (30 pages) about the matter, and whether to abandon the sighting of the moon for astronomical calculations. He too, like Al-Subki in 1348 C.E. was writing because of discrepancies in sighting across Muslim nations.

The summary is that he advocates for crescent sighting to be abandoned, because it was recommended when the nation was mostly made of nomadic people who are illiterate and can't calculate the time of the new moon. So it was easier to just sight it.

But later Muslims became very proficient in astronomy and excelled in it. They even measured the circumference of the earth, translated scientific books from Greek, and added their own observations and calculations in many Zijs (astronomical treatise and tables), and that legacy is with us today in the Arabic names of bright stars. I gave several talks at the local astronomy club on the topic. Check it here and here.

Shaker says that consequently, we should use calculation alone, and the moment of conjunction (Moon adjacent to the Sun). This is the same as we deal with the five daily prayer times, and how they are calculated (and not dependent on viewing the sun rising or setting, shadows or transiting the meridian). This used to be printed in calendars. He also says that 'possibility of sight' should not be considered either. Just that the moon has overtook the Sun.

He also says that communication has been revolutionized by the telegraph, telephone and radio, and therefore one city/village can know what others have decided by calculation.

Now 80 years after he wrote his booklet, we all have powerful computers in our pockets that show when the new moon is, just like we have apps that show the time for prayer. For the daily prayers, no one visually observes the astronomical phenomenon anymore:

• Dawn on the eastern horizon
• Actual sunrise
• Transit of the sun using a sundial or stick shadow
• Length of the shadows
• Sunset below the horizon
• End of twilight

Even in pre-modern times, there were contingency measures for when there is clouds that forbid the observation of such phenomenon, so calculations were necessary, even approximately, using an astrolabe.

If using astronomical calculations or phone apps is acceptable for daily prayers, then why not the conjunction of the moon? And even more: why does one pillar of Islam (Fasting) has one part by sighting of the moon, yet starting and breaking the fast is done using these modern day devices that are based on astronomical calculations? Isn't that a contradiction?

And astronomical calculations are accurate. How accurate? Accurate enough for the Hayabusa 2 spacecraft to chase an asteroid that is as far away or further than the sun, and land on it. And Accurate enough to send vehicles to the moon or Mars, without missing either.

We also have the internet to relay information to anyone with a phone.

You can read the original treatise here: أوائل الشهور العربية هل يجوز شرعاً إثباتها بالحساب الفلكي

Biography of Ahmed Shaker: أحمد محمد شاكر

And Shaker is not alone. There is also Al-Qaradawi advocating for astronomical conjunction back in 2005:
القرضاوي يرجح الحساب الفلكي

And Adnan Qadi الأهلة، نظرة شمولية و دراسات فلكية, also here, where he detailed many errors in witness vs. possibility of viewing. And a short video by him on a section of his book, relating to wrong sighting over many decades in Saudi Arabia.

There is also a book by Mostafa Abdel-Baset Ahmed advocating abandoning the sighting of the crescent in favour of astronomical conjunction: تحديد أوائل الشهور القمرية.. رؤية علمية شرعية

Further Reading

• Another book by Al-Subki: العلم المنشور في اثبات الشهور - تقي الدين السبكي
• الهلال بين الحسابات الفلكية و الرؤية by محمد شوكت عودة
• مركز الفلك الدولي various papers.
• توجيه الانظار لتوحيد المسلمين في الصوم و الافطار - ابو الفيض احمد بن محمد بن الصديق الغماري

So the final though is: will the Muslims ever finally catch on to the 20th century (let alone the 21st?)