Excerpt from the Book Ru’yat al-Hilāl by Fadhīlat al-Shaykh Maqṣūd al-Ḥasan Fayḍī
Preface
Allah, the Most Blessed and Exalted, states:﴿هُوَ الَّذِي جَعَلَ الشَّمْسَ ضِيَاءً وَالْقَمَرَ نُورًا وَقَدَّرَهُ مَنَازِلَ لِتَعْلَمُوا عَدَدَ السِّنِينَ وَالْحِسَابَ مَا خَلَقَ اللَّهُ ذَلِكَ إِلَّا بِالْحَقِّ يُفَصِّلُ الْآيَاتِ لِقَوْمٍ يَعْلَمُونَ﴾
Reference: Yūnus: 5
Translation:
“He is the One Who made the sun radiant and the moon a light, and determined for it phases that you may know the number of years and the reckoning. Allah did not create this except in truth. He explains the signs in detail for people who possess knowledge.”
This noble verse establishes a fundamental principle regarding the recognition of time, the knowledge of chronology and calculation, and the determination of months and years. Allah granted the sun its brightness and appointed stages for it so that the calculation of days and weeks may be known. Likewise, He granted the moon its light and appointed phases for it so that the reckoning of months and years may be easily determined.
Thus, Allah made the calculation of days and weeks so simple that both urban and rural people, the learned and the unlearned, can determine it with ease: when the sun rises, the day begins; when it sets, the day ends and night commences. When seven days and nights are completed, a week is completed. Similarly, when the new moon appears on the western horizon, a new month begins. When twenty-nine or thirty days are completed and the moon appears again, one month ends and another begins. When twelve months are completed, a year is completed.
Allah the Exalted says:
﴿إِنَّ عِدَّةَ الشُّهُورِ عِنْدَ اللَّهِ اثْنَا عَشَرَ شَهْرًا فِي كِتَابِ اللَّهِ يَوْمَ خَلَقَ السَّمَاوَاتِ وَالْأَرْضَ مِنْهَا أَرْبَعَةٌ حُرُمٌ ذَلِكَ الدِّينُ الْقَيِّمُ﴾
Reference: At-Tawbah: 36
Translation:
“Indeed, the number of months with Allah is twelve months in the Book of Allah from the day He created the heavens and the earth; of them, four are sacred. That is the correct religion.”
This is the calendar appointed by Allah, Lord of the Worlds, for all nations, through which people have conducted their religious and worldly affairs. However, due to following Satan and not being content with the simplest method, people abandoned this natural and legislated calendar and invented the innovations of Nasī’, Kabīsah, and Malmas.
The Arabs introduced two innovations regarding months and years:
① Nasī’ (Postponement): They would alter the sacred months by postponing or advancing them, permitting fighting in a sacred month and compensating by declaring another lawful month sacred.
② Kabīsah (Intercalation): They would add an extra month every third year to align the lunar year with the solar year so that Ḥajj would always fall in the same season.
Even the custodians of the Sacred Sanctuary were not free from this innovation, which disrupted the divinely established order of lunar months. When Allah perfected this upright religion, He restored the months to their original order and declared this to be the correct religion.
The Messenger of Allah ﷺ declared:
إن الزمان قد استدار كهيئته يوم خلق السماوات والأرض، السنة اثنا عشر شهرا منها أربعة حرم، ثلاث متواليات: ذو القعدة، ذو الحجة، والمحرم، ورجب مضر الذى بين جمادى وشعبان
Reference: Ṣaḥīḥ al-Bukhārī: 4662
Reference: Ṣaḥīḥ Muslim: 1679
Translation:
“Time has returned to its original state as it was on the day Allah created the heavens and the earth. The year is twelve months, of which four are sacred: three consecutive—Dhū al-Qaʿdah, Dhū al-Ḥijjah, and Muḥarram—and Rajab of Muḍar, which is between Jumādā and Shaʿbān.”
The Basis of Daily and Monthly Calculations
Allah made daily and weekly matters dependent upon the rising and setting of the sun. Regarding prayer, He says:﴿أَقِمِ الصَّلَاةَ لِدُلُوكِ الشَّمْسِ إِلَى غَسَقِ اللَّيْلِ وَقُرْآنَ الْفَجْرِ إِنَّ قُرْآنَ الْفَجْرِ كَانَ مَشْهُودًا﴾
Reference: Al-Isrā’: 78
Translation:
“Establish prayer from the decline of the sun until the darkness of the night, and (also) the recitation of Fajr. Indeed, the recitation of Fajr is witnessed.”
Monthly and yearly matters are connected to the moon. Regarding Ḥajj, Allah says:
﴿يَسْأَلُونَكَ عَنِ الْأَهِلَّةِ قُلْ هِيَ مَوَاقِيتُ لِلنَّاسِ وَالْحَجِّ﴾
Reference: Al-Baqarah: 189
Translation:
“They ask you about the new moons. Say: They are measurements of time for people and for Ḥajj.”
Thus, in Islam, lunar months are the fundamental basis for determining acts of worship and transactions. Even reliance upon non-Islamic months in religious matters has been deemed impermissible by scholars. Therefore, Amīr al-Mu’minīn ʿUmar ibn al-Khaṭṭāb رضي الله عنه, in consultation with the Companions, instituted the Hijrī calendar based on the moon.
The Means of Knowing the Sharʿī Months
Since all religious and worldly matters of Muslims are connected to lunar months, knowing their beginning and end is essential. The Sharīʿah has prescribed an extremely simple method: sighting the crescent (ru’yat al-hilāl) or completing thirty days.Allah says regarding Ramaḍān:
﴿فَمَنْ شَهِدَ مِنْكُمُ الشَّهْرَ فَلْيَصُمْهُ﴾
Reference: Al-Baqarah: 185
Translation:
“So whoever among you witnesses the month, let him fast it.”
The Prophet ﷺ said:
إذا رأيتموه فصوموا وإذا رأيتموه فأفطروا، فإن غم عليكم فاقدروا له
Reference: Ṣaḥīḥ al-Bukhārī: 1900
Reference: Ṣaḥīḥ Muslim: 1080
Translation:
“When you see it (the moon), then fast; and when you see it, then break the fast. If it is obscured from you, then complete the count (thirty).”
He ﷺ also said:
إنا أمة أمية لا نكتب ولا نحسب، الشهر هكذا وهكذا وهكذا...
Reference: Ṣaḥīḥ al-Bukhārī: 1903
Reference: Ṣaḥīḥ Muslim: 1080
Translation:
“We are an unlettered nation; we neither write nor calculate. The month is like this and like this and like this,” indicating sometimes twenty-nine and sometimes thirty days.
Benefits Derived from the Aḥādīth
① In Sharʿī matters, especially acts of worship, only lunar months are معتبر (valid and authoritative).② The only means of determining the beginning and end of a month is sighting the crescent; reliance upon astronomical calculations is not permissible.
③ A month is either twenty-nine or thirty days—never less nor more.
④ The condition of sighting was legislated because it is simple, certain, and free from error.
⑤ If astronomical calculations claim the moon is present but it is not sighted, calculation is not relied upon. If trustworthy witnesses sight it, their testimony is accepted even if calculations differ. There is consensus (ijmāʿ) on this matter.
⑥ Not only fasting and ʿĪd, but also zakāh, waiting periods (ʿiddah), oaths, loans, and other matters are determined according to lunar months.
Beginning and End of Sharʿī Months
A Sharʿī month begins only with the sighting of the crescent after sunset or by completing thirty days. If the moon is seen before sunset, it is not considered valid for commencing the new month. The Prophet’s ﷺ statement:صوموا لرؤيته وأفطروا لرؤيته
means fasting or breaking the fast is based on the sighting that occurs after sunset.
Reference: Fatḥ al-Bārī: 4/131
Difference Between Sharʿī Months and Astronomical Months
A Sharʿī month consists of twenty-nine or thirty complete days, each day being twenty-four hours. Astronomers, however, begin the month at conjunction (when the moon aligns between the earth and sun), regardless of visibility. This may occur at any hour—day or night.Thus, the astronomical month may begin up to twenty-four hours or more before the Sharʿī month. Astronomers state the average lunar month is 29 days, 12 hours, and 44 minutes.
The New Moon (Conjunction)
When the moon becomes completely invisible, this moment is called conjunction (CONJUNCTION). The interval between two conjunctions averages 29 days, 12 hours, and 44 minutes. However, this does not mean the crescent will be visible that same night, as it may be extremely thin and obscured by twilight.A one-day-old moon is extremely thin—comparable to a very narrow slice of a melon divided into thirty equal parts.
For further detail, see:
Reference: Abḥāth Hay’at Kibār al-ʿUlamā’: 3/10
And the book Al-Shams wa al-Qamar bi Ḥusbān by Mawlānā ʿAbd al-Raḥmān Kilānī رحمه الله.
