The Indonesian Ministry of Religious Affairs (Kemenag) has officially set 1 Muharam 1448 Hijriah for Tuesday, June 16, 2026, based on the MABIMS criteria for hilal visibility. Meanwhile, the Executive Board of Nahdlatul Ulama (PBNU) has declared the date to be Wednesday, June 17, 2026, following reports that the new moon was not sighted during their observations.
Why the dates differ
The discrepancy arises from the varying methodologies used by the two organizations to determine the start of the Islamic month. According to Arsad Hidayat, Director of Islamic Religious Affairs and Sharia Guidance at Kemenag, the ministry utilizes the MABIMS criteria—a standard agreed upon by Brunei, Indonesia, Malaysia, and Singapore. These criteria require a minimum hilal altitude of 3 degrees and an elongation of 6.4 degrees.
Kemenag data from June 15, 2026, showed the hilal altitude ranging from 0.92 degrees in Merauke to 4.02 degrees in Sabang. Because these parameters met the MABIMS requirements, the ministry declared the start of the month as June 16. In contrast, PBNU conducted its own rukyatul hilal (visual sighting) on June 15 and reported that the hilal remained unseen across all monitoring points. Consequently, PBNU opted for the istikmal method, which rounds out the current month to 30 days, pushing the start of the new month to June 17.
The role of astronomical data
Ismail Fahmi, Sub-director of Hisab Rukyat and Sharia, explains that Indonesia recognizes multiple approaches, including rukyatul hilal (physical sighting), wujudul hilal, and imkanur rukyat. The imkanur rukyat method is designed to bridge the gap between physical observation and astronomical calculation. It relies on long-term data analysis, allowing officials to maintain accurate calendars even when weather conditions, such as cloud cover, prevent a clear view of the moon.
What happens next
As the two dates are now officially observed by different groups, the public is likely to see variations in the scheduling of local events and commemorations. Kemenag has expressed that it respects the PBNU decision and views the difference as part of the country’s diverse scholarly landscape. Moving forward, authorities expect that continued communication regarding these methods will help improve public literacy concerning the complexities of hisab-rukyat.
Frequently Asked Questions
Why did Kemenag choose June 16?
Kemenag determined that the calculated position of the hilal met the MABIMS criteria of at least 3 degrees in altitude and 6.4 degrees in elongation, making June 16 the start of the month.
Why did PBNU choose June 17?
PBNU conducted rukyatul hilal observations on June 15 and, because the hilal was not sighted at any location, they applied the istikmal method to complete the month, setting the start date for the following day.
Is there a conflict between these two organizations?
No. Kemenag has explicitly stated that it respects the decision of PBNU, and officials have emphasized that different methods of determining the lunar calendar are a normal part of the Islamic scholarly tradition in Indonesia.
How will your community be observing the start of the new Hijriah year?
