Explained: 4 Methods Countries Use To Determine Start Dates For Ramadan, Eid

2026-02-05 04:21:11

(MENAFN- Khaleej Times)

From moon sighting to astronomical dates, there is no singular system that is applied all over the Muslim world to spot the crescent in the evening sky

PUBLISHED: Thu 5 Feb 2026, 12:51 PM

By:
Yasmin Hussein

Every Hijri month, observers and religious scholars across the Muslim world turn their eyes to the western horizon in search of the tiny crescent moon. Excitement and anticipation around spotting this delicate celestial sliver peaks particularly at some points of the year - like Ramadan - as its appearance carries significant social and religious implications.

The Islamic (Hijri) calendar follows the lunar cycle, which means that the start of each of its 12 months is determined by the sighting of the crescent moon, known in Arabic as "Al hilal". Each month lasts either 29 or 30 days, depending on when the new crescent is first seen.

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Moon-sighting happens on the 29th day of each Hijri month. If it is seen, the new Hijri month starts on the following day. If not, the current Hijri month completes 30 days, and then the new one commences on the following day. But how is this start date determined?

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Here are some key questions on the monthly event answered:

Four methods

There isn't a singular moonsighting system that is applied all over the Muslim world. Each country uses one of the following four approaches to spot the crescent in the sky:

1. Local physical sighting (Ru'yah)

This method relies on direct human observation of the crescent using the naked eye. The sighting is confirmed by the actual spotting of the thin crescent moon in the evening sky after Maghrib prayer. Observers look toward the western horizon, and any confirmed sighting - by the naked eye or sometimes optical aids - is reported to an official religious authority, such as a moon-sighting committee or court. Authorities then announce the official results to the public.

2. Astronomical calculations

This method uses scientific data, such as the time of conjunction, moon altitude, and visibility criteria, to determine when the crescent can be seen. It is followed by some countries, especially where sighting is difficult.

In Singapore, for instance, limited viewing space and consistently cloudy weather make the physical observation of the crescent moon particularly difficult. "As a result, Singapore has adopted the Hisab (calculation) method since 1974 to determine the beginning of Hijri months," Majlis Ugama Islam Singapura (MUIS), the official Islamic Religious Council of Singapore, said.

3. Standard method

In some cases, Muslims follow the crescent moon sighting or calendar of another country with an established Islamic authority - often the nearest Muslim-majority country or a location like Makkah - to decide when the Islamic month begins.

Antarctica, for example, has no permanent Muslim population or official Islamic institutions, so there isn't a unique moonsighting system there the way countries have formal committees to declare crescent sightings. Muslims who happen to be in there, like researchers or staff at research stations, adapt by using this approach to sighting.

4. Hybrid approach

This method combines astronomical calculations and physical sighting. Calculations are used to determine whether sighting is astronomically possible and to guide observers, but the final decision still depends on an officially confirmed sighting announced by religious authorities. Calculations support the process but do not replace it, and Muslims have to wait for official announcements of sighting results.

Are there any special conditions?

Muslims performing Hajj each year must abide by Dhul Hijjah's crescent moon sighting in Saudi Arabia, since the date is closely related to standing on Mount Arafat in Makkah on Dhul Hijjah 9 to complete the most important part of their spiritual journey.

Why are some dates so special?

The crescent moon sighting is performed every month. However, on some occasions, the event becomes of major religious and social significance. Hence, Muslims look forward to announcements regarding the starting date of the following Hijri months in particular:

Ramadan: The holy fasting month is the ninth Hijri month on the calendar. Muslims' daily lives usually change dramatically, and the start date of the month is highly anticipated. One Hadith says:“Fast when you see it (Ramadan's crescent moon), and break your fast when you see it (Shawwal's crescent moon). If it is obscured (by clouds), complete the month of Shaban as thirty days.”

Shawwal: It is the month that follows Ramadan. Shawwal 1 marks the beginning of Eid Al Fitr.

Dhul Hijjah: The sighting of the Dhul Hijjah crescent moon is of great importance as Dhul Hijjah 9 marks the Day of Arafat, followed by Eid Al Adha. It includes the peak of the annual Hajj season.

Muharram: It is the first month on the Hijri calendar. On Muharram 10, Muslims observe the day of Ashoura. However, Muharram's crescent moon sighting is less publicly observed.

Rabi Al Awwal: It is the month when Muslims observe the birthday of Prophet Mohammed (PBUH) on the 12th day of the month.

Why do Hijri months start on varying dates in Muslim countries?

Differences in weather, cloud cover, and geographic location can affect whether the crescent is visible in some places and not in others, meaning one country may see it a day before another.

In addition to this, time zones also play a role. The crescent may be visible in one location but not another on the same evening due to longitude, latitude, or local terrain. The sighting process itself may take place on different dates, as each month, the crescent moon of the new Hijri month is sighted.

Who performs the sighting?

Most Muslim countries appoint government or religious authorities to form committees responsible for verifying and announcing the sighting of the crescent moon. Trained observers and volunteers often go to high points or clear horizons to physically spot the crescent. Astronomers may also assist in the process, and all observers report their findings to the official committee.

The UAE observatories that participate in the crescent sighting are: