Singapore’s approach to determining the start of the Islamic hijri month

Knowing the start of the hijri month in the Islamic calendar is particularly important for Muslims as there are significant acts of worship which rely on it. For example, the fasting of Ramadan, the fasting of Arafah, the celebration of both Hari Raya Aidilfitri and Hari Raya Aidiladha and the hajj, to name a few, fall on specific dates in the hijri calendar. 

Without knowing the dates, it will be difficult to observe the aforementioned deeds.

Read: 4 Intriguing Things You May Not Know About the Islamic Hijri Calendar

In a hadith, the Prophet s.a.w. said:

إِذَا رَأَيْتُمُ الْهِلاَلَ فَصُومُوا وَإِذَا رَأَيْتُمُوهُ فَأَفْطِرُوا فَإِنْ غُمَّ عَلَيْكُمْ فَصُومُوا ثَلاَثِينَ يَوْمًا

"When you see the new moon (of Ramadan), then fast. And when you see the new moon (of Syawal), then stop fasting. But should it cloud over, then fast for 30 days."

(Sunan An-Nasai)

This hadith tells us that the sight of the new moon determines the beginning of a new hijri month on the following day.

Does it literally mean to witness a new moon? or could it mean that we can determine by the advent of the new moon itself whether or not we can visibly see it? Scholars have deduced several ways to determine.

This article intends to address the issue of moonsighting to determine the start of the hijri months in Islam.

1. What is Singapore’s approach to determining the date for the beginning of the hijri month?

From the perspective of the Shariah, there are two widely accepted methods to determine the new months in Islam.

Image from Islamic Religious Council of Singapore's e-book: Navigating Tradition and Science - Singapore’s Approach in Determining the Hijri Calendar

Both methods align with a hadith narrated by Ibn Umar r.a. where the Prophet Muhammad s.a.w. said:

 إذا رَأَيْتمُوه فَصُومُوا، وإذا رَأَيْتُمُوه فَأفْطِروُا، فإن غُمَّ عليكم فَاقْدُرُوا له

"Begin your fast when you can observe the new moon (of Ramadan), and end it when you can observe it (the new moon of Syawal). But should it cloud over, you can predict its visibility (through calculations)"

(Muttafaqun 'Alayh)

Due to the climate and several other factors, it is very difficult for the new moon (at its early age) to be sighted in Singapore. Hence, Singapore uses a method based on Imkan ar-Rukyah (calculating the possibility of visible moonsighting) to determine the beginning of the hijri month.

For the new moon to be sighted, astronomers have set some parameters. The conditions required for the new moon to be visible depend on the altitude of the new moon from the horizon and the elongation (angular distance) between the moon and the sun during sunset. Both mentioned criteria must meet a certain measurement for the moon to be visible by the naked eye or by a regular telescope.

Hence, on the 29th day of every hijri month, the moon must meet the criteria of Imkan Ar-Rukyah to officially announce the start of a new hijri month.

Image from Islamic Religious Council of Singapore's e-book: Navigating Tradition and Science - Singapore’s Approach in Determining the Hijri Calendar

The announcement is usually made for Ramadan, Syawal and Zulhijjah, all of which involve significant acts of worship, as mentioned above.

On 1 May 2022, Mufti was seen using the telescope in an attempt to observe the new moon. However, the observation was explicitly made to assess a possible established need to confirm the calculation of the new moon and to collect data for research and future observations. 

What many may think that Mufti adopts the Rukyah (sighting by the naked eye) method is actually to collect data and not to determine a hijri month.

2. Based on the Imkanur Rukyah method, can Singapore see the new moon and meet the criteria?

Since 2017, experts in astronomy have discussed and revised the criteria of Imkan Ar-Rukyah. The new criteria were developed and determined based on the results of more than 700 observation data collected from all over the world. 

The new criteria only need two parameters during sunset, on the 29th day of every hijri month:

a.    The altitude of the new moon
b.    And the elongation between the sun and the moon.

The moon's altitude must exceed 3°, and the elongation must exceed 6.4°.

If the position of the new moon at sunset does not meet the criteria scientifically (astronomical) and based on the data from the 700 observations mentioned earlier, the new moon cannot be seen with the naked eye or even with the aid of optical observation equipment (regular telescope, binoculars, etc) at sunset.

In addition to that, the new moon is even more difficult/impossible to observe in Singapore due to several reasons, among others, weather factors, atmospheric contamination and thick clouds. Singapore is one of the countries which experience very frequent thunderstorms. We receive about 170 days of lightning thunderstorms in a year.

3. What happens when we cannot visibly witness the new moon?

If the new moon is not visibly seen, the next day is still considered to be the same month we're in.

So if the new moon cannot be seen on the 29th of Ramadan, it means that we have to fast another day and thus complete it to 30 days of fasting altogether. 

This based on the aforementioned hadith:

إِذَا رَأَيْتُمُ الْهِلاَلَ فَصُومُوا وَإِذَا رَأَيْتُمُوهُ فَأَفْطِرُوا فَإِنْ غُمَّ عَلَيْكُمْ فَصُومُوا ثَلاَثِينَ يَوْمًا

"When you see the new moon (of Ramadan), then fast. And when you see the new moon (of Syawal), then stop fasting. But should it cloud over, then fast for 30 days."

(Sunan An-Nasai)

 Sunrise at the eastern horizon of Singapore

4. When will Singapore celebrate Hari Raya Aidilfitri this year?

Astronomical calculations show that on 29 Ramadan 144H / 20 April 2023, the new moon is unlikely to be visible on the western horizon of Singapore as the sun sets in the evening. Moreover, it does not meet the requirements of the Imkan Ar-Rukyah criteria (The altitude of the new moon must exceed 3° and the elongation must exceed 6.4°).

The altitude of the moon on 20 April at sunset will be at 1.7° with an elongation of almost 2.6°. With the criteria unfulfilled, it is unlikely that the new moon will be visible, even with the aid of an optical observation device.

Therefore this year in 2023, Singapore will likely start the month of Syawal and thus celebrate Hari Raya Aidilfitri on 22 April instead of 21 April. However, do note that we would have to wait for Mufti's announcement to officially declare the date of Hari Raya Aidilfitri

5. Will there be any expected differences in dates for Syawal by other countries? And in general, has these differences ever occurred in history before?

There is no denying that there is a possibility that some Muslim countries (whether in this region or the Middle East) will announce the date for Hari Raya Aidilfitri a day earlier.

Each country has its respective process and the right to independently determine the new hijri month. Islam allows room for such diversity. In fact, it's important to know that this has happened before during the time of the companions of the Prophet r.a.

Imam Muslim has narrated the differences in determining the dates for the beginning and end of fasting for Ramadan amongst the companions who resided in different cities.

Sayyidina Mu’awiyah r.a. began fasting for Ramadan on Friday, while those in the city of Madinah started to fast on Saturday. This happened due to the differences in seeing the new moon between the two cities of Syam (the Levant) and Madinah, respectively.

When the residents of Madinah asked, “Why not follow Sayyidina Mu’awiyah r.a. to align the fasting period among Muslims as the new moon has already been seen in Syam?” Sayyidina Ibn ‘Abbas r.a. replied that this was how Rasulullah s.a.w. taught them to determine the start of a hijri month (according to the respective location resided by the individual or community), even if it may lead to differences among Muslims at that time.

6. If there are members of the community who claim to have witnessed the new moon, while it does not meet the criteria for its appearance that has been agreed upon by astronomers, how can this be clarified?

Observing the new moon is a field that requires competent knowledge. For example, to know:

a. The right geographical direction for the observation.
b. The height of altitude of the moon and distance of elongation.
c. The shape of the new moon
d. The time of observation
e. The age of the new moon, and so on.

So, for example, in observing the new moon, the observer must ensure that the new moon is located at the western horizon and not the eastern horizon. This is to differentiate between the ‘old moon’ and the new moon. If anyone claims to have witnessed the new moon at the eastern horizon, then it is not a new moon but possibly an ‘old moon’.

It is mentioned in the Book of Tuhfah At-Tullab, by Sheikhul Islam Zakariyya Al-Ansari, one of the main references for the Syafi’i fiqh school of legal thought (mazhab) – that if anyone witnesses the new moon, but it contradicts with the findings from the science of astronomy, then the claim is rejected.

Read the e-book: Navigating Tradition and Science - Singapore’s Approach in Determining the Hijri Calendar