Eid 2025 Potentially the Same, Momentum to Reunite the Indonesian Hijri Calendar

Eid al-Fitr 1 Shawwal 1446 Hijri will most likely be celebrated simultaneously by Indonesian Muslims on Monday, March 31, 2025. Although this alignment of Eid 2025 occurs due to the favorable position of the crescent moon, this situation should be utilized to reunite all Islamic mass organizations in order to achieve a unified Hijri calendar for Indonesia.

Ijtimak or conjunction indicating the moon (moon) dies as a sign of the end of the month (month) of Ramadan and the beginning of the month of Shawwal took place on Saturday (3/29/2025) or 29 Ramadhan 1446 at 17.57 WIB, 19.57 WIT, or 10.57 universal time (UT). Meanwhile, the maghrib time or when the sun sets in Indonesia on that day takes place between 17.44 WIT and 18.48 WIB.

Across Indonesia, only in Jakarta, Banten, and Sumatra does the conjunction occur before sunset. Therefore, only in these regions is it possible to conduct the observation of the crescent moon as the basis for determining the start of the Hijri month. Based on the concept of a unified legal territory, if the crescent moon has formed or been observed in one region of Indonesia, other regions will follow suit.

The crescent moon has the potential to be observed (imkan rukyat) if it has a minimum height of 3 degrees and an elongation or angular distance between the Sun and the Moon of at least 6.4 degrees.

This is the minimum threshold for the position of the crescent moon used in the criteria for the beginning of the Hijri month by the Ministers of Religious Affairs of Brunei Darussalam, Indonesia, Malaysia, and Singapore (MABIMS). These criteria are utilized by the Ministry of Religious Affairs, Nahdlatul Ulama, Persatuan Islam, several other Islamic mass organizations, as well as member countries of MABIMS.

Based on data from the Meteorology, Climatology, and Geophysics Agency, at sunset on Saturday evening (29/3/2025), the height of the crescent moon reached minus 1.85 degrees in Jakarta to minus 1.08 degrees in Banda Aceh. The elongation of the crescent moon reached 1.06 degrees in Jakarta to 1.21 degrees in Banda Aceh.

With that data, at sunset on the 29th of Ramadan 1446, the crescent moon will still be below the horizon due to its negative altitude. The elongation of the crescent, which is far below the new MABIMS criteria threshold, also makes the crescent unobservable because the Moon's position is still too close to the Sun. As a result, the crescent is impossible to observe, meaning it cannot be sighted.

Because the data from hisab and rukyat yield the same result, it is highly likely that the isbat session will determine the duration of the month of Ramadan to be 30 days, and Eid al-Fitr will also fall on Monday (31/3).

Since the crescent moon could not be observed on Saturday evening (29/3), the consequence is that the duration of the month of Ramadan will be completed to 30 days. Thus, Eid al-Fitr 1 Shawwal 1446 H is likely to fall on Monday (31/3).

Meanwhile, the criteria for the formation of the crescent moon (wujudul hilal) adopted by Muhammadiyah requires that the beginning of the Hijri month occurs if the conjunction occurs before sunset, the crescent moon is above the horizon, meaning the sun sets before the moon.

In fact, from Jakarta to Banda Aceh, in addition to the crescent moon still below the horizon, the Moon also sets earlier than the Sun. In Jakarta, the Moon sets six minutes earlier than the Sun and in Banda Aceh, the Moon sets four minutes earlier than the Sun.

So, with the criteria of the crescent moon, the crescent moon has not formed on Saturday evening. Therefore, the age of the month of Ramadan is completed 30 days and Eid falls on Monday (31/3).

This condition shows that Muslims who use rukyat (empirical) and hisab (hilal existence) will most likely celebrate Eid al-Fitr 1446/2025 together on Monday (31/3). The estimated fall of Eid on Monday (31/3) is also stated in the Hijri calendar issued by the Ministry of Religion, NU, Muhammadiyah, Persis, and other Islamic mass organizations.

Although theoretically rukyat will not be able to see the crescent moon on Saturday (29/3) evening, the government and various Islamic mass organizations will still observe the crescent moon. This crescent moon observation is to carry out religious orders which are obligatory kifayah (if one person has done it then the other obligation is dropped), as well as proof of the calculations (hisab) they have done.

The results of the observation will be brought to the isbat or determination session that will be carried out by the Ministry of Religion on Saturday (3/29) night to compare the hisab data and the rukyat results. Because the hisab and rukyat data produce the same results, it is likely that the isbat session will determine the age of the month of Ramadan is 30 days and Eid al-Fitr will also fall on Monday (3/31).

Togetherness in starting Ramadan and celebrating Eid al-Fitr 1446/2025 can be a momentum to immediately realize one Indonesian Hijri calendar.

However, the similarity of Eid al-Fitr 1446/2025 will not be realized if Muhammadiyah has implemented the Single Global Hijri Calendar (KHGT) system. This KHGT system will replace the criteria for the existence of the crescent moon and the final plan will start to be used in 1447/2026.

KHGT has the principle of one day one date for the whole world. This calendar system also uses imkan rukyat but is global. The beginning of the Hijri month in KHGT is determined on the condition that ijtimak occurs before 00.00 universal time (UT) aka 00.00 Greenwich, England (GMT) and the position of the crescent anywhere on the face of the Earth has a minimum height of 5 degrees and a minimum elongation of 8 degrees.

With these conditions, the initial conjunction of Syawal 1446 occurred on Saturday (3/29) at 10:57 UT. At that time, the crescent moon in the North American region already had a height of more than 5 degrees and an elongation of more than 8 degrees. Thus, with KHGT, the age of the month of Ramadan 1446 is only 29 days and Eid al-Fitr will fall on Sunday (3/30) or a day earlier than what the government will likely decide.

The use of KHGT is the right of Muhammadiyah. However, the use of this system is feared by many groups to make the difference in the beginning of Ramadan, Eid al-Fitr, and Eid al-Adha more frequent in Indonesia.

Professor of Astronomy at Walisongo State Islamic University, Semarang, Ahmad Izzudin, who is also the General Chairperson of the Indonesian Astronomy Lecturers Association, Wednesday (26/3), hopes that togetherness in starting Ramadan and celebrating Eid al-Fitr 1446/2025 can be a momentum to immediately realize one Indonesian Hijri calendar.

All Islamic mass organizations actually have the same intention and determination to unify the various criteria of the Hijri calendar. However, this effort will never be realized if each mass organization insists on its principles. This determination should be able to be developed into a joint agreement for the benefit of Indonesian Muslims.

Astronomy and astrophysics researcher who is also a lecturer in the Physics Education Study Program at the Indonesian Education University in Bandung, Judhistira Aria Utama, added, "Every Islamic mass organization needs to open itself to be willing to better understand the mindset of other mass organizations." This attitude of mutual understanding must also be accompanied by a willingness to change for the greater good of the community.

The founder of the Imah Noong Observatory and Planetarium, Lembang, West Bandung, Hendro Setyanto, believes that togetherness in starting Ramadhan, Syawal, and Zulhijah in Indonesia can only be achieved if all Islamic mass organizations submit this issue to the government. However, the handover of authority to determine the beginning of the Hijriah month has been a debated issue for a long time.

So far, the government has tried to accommodate the interests of all Islamic mass organizations, both those using hisab or rukyat as well as modern astronomical science in compiling the Hijri calendar in Indonesia, both through the isbat session mechanism and the new MABIMS criteria.

However, not all mass organizations are willing to follow the provisions that have been made together with the Indonesian Ulema Council, Islamic mass organizations, as well as astronomers from universities and Islamic boarding schools, and national research institutions.

The existing Hijri calendar system, both in Indonesia and in other Muslim countries, still has a number of problems.

Apart from the willingness of all Islamic mass organizations to side with the interests of the greater community, the existing Hijri calendar system, both in Indonesia and in other Muslim countries, still has a number of problems.

One of the fundamentals according to Izzudin is the absence of an agreement on the philosophical basis for determining the beginning of the Hijri month, namely empirical rukyat or hisab which is compiled based on the existence of hisab. As a result, the definition of the hilal alone still has differences until now.

Determining the beginning of the Hijri month with rukyat at the beginning of each month, continued Judhistira, makes the Hijri calendar have high uncertainty and is difficult to use for long-term planning. "A long-term predictive calendar can only be produced through hisab," he said.

To accommodate rukyat, the criteria for the beginning of the Hijri month can be determined based on the imkan rukyat or the possibility of seeing the crescent moon. If the interests of hisab and rukyat practitioners have been equally accommodated in the criteria for the beginning of the Hijri month, then all parties must be happy to accept the results of the hisab in full in the calendar.

"The ideal Hijri calendar cannot depend on rukyat because it will make the function of the calendar as a time indicator for humans not work perfectly," added Hendro.

However, the calendar that is compiled based on the hisab imkan rukyat will not eliminate the practice of rukyat at the beginning of each Hijri month. However, whatever the results of the rukyat obtained, it must not change the existing hisab calendar.

In this way, the function of the calendar for civil administration and for worship will be separated. The function of the calendar for civil administration is arranged based on hisab, while rukyat is used to determine the time of worship, not to determine the beginning of the Hijri month.

The separation of the functions of the calendar and rukyat was once carried out by Nahdliyin residents in Muharam 1446. At that time, although the NU calendar set 1 Muharam on July 7, 2024, because the crescent moon failed to be observed, 1 Muharam was finally set on July 8, 2024. This decision did not change the existing calendar, but only shifted the worship time of residents who wanted to carry out the Muharam sunat fasting.

Education for the people is important so that they are able to tolerate different groups, not feel that they are the most correct, or bring down those who have different views.

While waiting for an agreement to be reached to realize a single Hijri calendar in Indonesia and finding common ground on the existing differences and shortcomings, Izzudin continued, education of the people is important so that they are able to tolerate different groups, not feel that they are the most correct, or bring down those who have different views.

"If it cannot be united, it is okay because differences in worship are common and cannot be forced to become one," he added. Moreover, in the perspective of fiqh, the implementation of worship is indeed based on each person's beliefs so that efforts to unify the Hijri calendar will certainly not be easy.

For almost the last four decades, people have become accustomed to the differences between Ramadhan, Eid al-Fitr and Eid al-Adha, thus fostering an attitude of mutual understanding.

However, these differences do not need to be exacerbated in debates on social media which often only cause chaos, even ending up becoming legal problems as happened several years ago.

The government has also given freedom to the community in determining the beginning of the Hijri month. Therefore, Hendro continued, all parties need to restrain themselves from showing their differences for the common good. Manners in dealing with differences need to be more emphasized in order to maintain harmony and unity of the people.