Moon Observation and the Beginning of Ramadan

Hilal (Arabic: هلال) is the term for the thin crescent moon that becomes visible shortly after the new moon. In the Islamic calendar, the observation of hilal marks the beginning of a new month. Since the Islamic calendar is a pure lunar calendar, each month consists of either 29 or 30 days, depending on when the new hilal is observed.

The new moon (conjunction) is the astronomical moment when the Moon is positioned between the Earth and the Sun. At this point, the Moon is invisible. Only when the Moon moves further in its orbit and a small part of its illuminated surface faces the Earth can hilal potentially be observed – typically 15-24 hours after conjunction.

It is important to distinguish between the actual birth of the new moon (a precise astronomical moment) and the visibility of hilal (which depends on location, atmospheric conditions, and the Moon's angle above the horizon). This difference is at the core of many of the disagreements that arise.

The Islamic practice of moon observation is rooted in both the Quran and the traditions of the Prophet (peace be upon him).

This hadith is the central basis that all schools of law take as their starting point. The disagreement arises in the interpretation: Does "see" (صوموا لرؤيته) mean that one must physically see the moon with the eye? Or does it merely mean to "ascertain" – that is, to gain certainty that the new month has begun, regardless of the method? [3]

There are fundamentally three approaches to determining when a new Islamic month begins:

Ru'yah (رؤية, "to see") is the oldest and most widespread method. After sunset on the 29th day of a month, observers look toward the western horizon to find the thin crescent moon. If hilal is observed, the new month begins the next day. If it is not observed, the current month is completed with 30 days. [2]

The advantage of ru'yah is that it follows the Prophet's practice literally. The disadvantage is that it is vulnerable to weather conditions – overcast weather can make observation impossible, and in northern countries like Denmark, long twilight periods can make it difficult to discern the crescent.

Astronomical calculation uses mathematical models to determine precisely when the new moon is born (conjunction) and when hilal is theoretically visible from a given location. Modern astronomy can predict these moments with a precision of less than one second.

There are several criteria for when the crescent is considered "visible" in calculation models:

Proponents of calculation argue that astronomy is an exact science that eliminates human errors and weather dependence. Critics claim that calculation replaces a God-given practice with human systems, and that the Prophet's words specifically mention "seeing" the moon. [2]

Many modern organizations use a combination: astronomical calculation is used to rule out false observations (if astronomy says the moon cannot possibly be seen, witness testimonies are rejected), while the final confirmation still requires physical observation.

This approach accommodates both traditionalists and modernists. The European Council for Fatwa and Research (ECFR) and several Northern European Islamic councils use this hybrid method. [13]

Even within Sunni Islam, there are notable differences between the four major schools of law (madhahib) when it comes to moon observation. The disagreement primarily concerns two questions: how many witnesses are required, and does an observation apply locally or globally?

The Hanafi school distinguishes between clear and overcast weather: [7]

• Clear weather: A large number of witnesses (jamm ghafir) is required to confirm the observation, since the moon should be visible to many if the sky is clear.
• Overcast weather: One reliable Muslim's testimony is sufficient, since it is understandable that only few have seen it.

Regarding scope, most Hanafi scholars hold that a confirmed observation in one place is binding for all Muslims, regardless of distance – so-called ittihad al-matali' (unity of horizons). This means that if the moon is seen in Morocco, Muslims in Indonesia should also begin the new month. [7]

The Maliki school requires at least two reliable witnesses to confirm the moon observation, regardless of weather conditions. The witnesses must be adult, sane Muslims with a good reputation ('adl). [8]

Regarding geographical scope, Maliki scholars acknowledge that an observation in one region should be followed by nearby regions. However, they are more nuanced than the Hanafi school – very distant countries do not necessarily need to follow an observation made on the other side of the globe. [8]

The Shafi'i school accepts one reliable witness's testimony to confirm the beginning of Ramadan – even in clear weather. Imam al-Shafi'i based this on the hadith about Ibn Umar, who reported his observation to the Prophet, who then ordered fasting. [9] [10]

On the other hand, the Shafi'i school is the most restrictive regarding geographical scope. It follows the principle of ikhtilaf al-matali' (difference of horizons): each area should follow its own local observation. The reasoning is that the moon's visibility varies with latitude, so an observation in the Middle East is not necessarily relevant for Scandinavia. [10]

The Hanbali school requires one reliable witness for the beginning of Ramadan, but two witnesses to confirm Eid (the end of the month). This asymmetry is due to the precautionary principle: it is better to fast one day too many than one day too few. [11]

Like the Hanafi school, most Hanbali scholars hold that one confirmed observation applies globally for all Muslims. Imam Ahmad ibn Hanbal stated that if a reliable person's testimony is accepted by a judge, it is binding for all. [11]

Shia Islam – primarily the Ja'fari school (Twelver Shia) – has a distinct approach to moon observation that often leads to Shia Muslims beginning Ramadan 1-2 days after Sunni Muslims.

Why is Shia often 1-2 days "behind"? The stricter witness requirements (always two witnesses + naked eye) make it harder to confirm an observation. Additionally, many Shia Muslims follow Ayatollah Sistani or Ayatollah Khamenei, both of whom set high standards for confirmation. Saudi Arabia's declaration, which many Sunni countries follow, is typically not accepted by Shia scholars. [14]

Internal Shia differences: Even among Shia Muslims, dates can vary. Followers of Ayatollah Sistani (Iraq) may have one date, while followers of Ayatollah Khamenei (Iran) have another. Ismaili Shia follow yet a third system based on calculation.

One of the most debated questions in Islamic jurisprudence is whether a moon observation in one place on Earth applies to all Muslims globally. This question has two classical positions:

In practice, very few countries follow pure global observation. Most follow either local observation, regional observation (e.g. "nearest Muslim country"), or their government's official declaration.

In modern times, different countries and organizations have developed their own systems:

When all these factors are combined, it is clear why the start date of Ramadan can vary by up to 2-3 days across the Muslim community:

Scandinavia has particular challenges when it comes to moon observation:

• Northern latitude: Denmark (55-57 degrees N), Sweden, and Norway (up to 71 degrees N) have long twilight periods, making it difficult to see the thin crescent.
• Weather conditions: Frequent cloud cover, especially in winter, makes physical observation unreliable.
• Bright summer nights: In June and July, there is almost no darkness, making observation practically impossible in northern Scandinavia.
• No central authority: There is no official Islamic authority in the Nordic countries, so mosques and organizations choose their own method and authority to follow.

In practice, most Scandinavian mosques follow either:

• Saudi Arabia's declaration (especially Arab and Southeast Asian mosques)
• Turkey's Diyanet calculation (Turkish mosques) [15]
• ECFR's recommendations (certain European-oriented organizations) [13]
• Their home country's declaration (Somali, Pakistani, Moroccan, etc.)
• A local Shia marja's declaration (Shia mosques) [14]

The result is that in Danish cities like Copenhagen and Aarhus, one can experience different mosques beginning Ramadan on different days – which can be confusing but reflects the rich tradition of legitimate legal disagreement in Islam.

Moon observation (hilal) is a central topic in Islamic practice that directly affects when billions of Muslims begin and end Ramadan, as well as celebrate the two major holidays Eid al-Fitr and Eid al-Adha. The differences between Sunni and Shia, and even between the four Sunni schools of law, are not due to ignorance or division, but a rich tradition of legal interpretation (ijtihad) within Islamic law.

For Muslims in Denmark and Scandinavia, the challenge is particularly great, as the northern latitudes, frequent cloud cover, and the lack of a central Islamic authority make it practically impossible to carry out reliable local moon observation. The most important thing is to follow your local mosque or your scholarly authority – disagreement about the date is part of Islamic tradition and not a cause for division.

Praay.org uses astronomical calculations based on the Umm al-Qura calendar to indicate the expected dates of Ramadan. These dates are indicative and may deviate by 1-2 days from the final declaration in your local community. Always check your mosque's official announcement for the final date.