BMKG Forecasts Eid al-Fitr 2026 to Fall on 21 March
Indonesia’s Meteorology, Climatology, and Geophysics Agency (BMKG) has forecast that Eid al-Fitr 1447 Hijriah is likely to fall on Saturday, 21 March 2026.
The forecast is based on a map of hilal altitude for 2026 released by BMKG to monitor the possibility of observing the young crescent moon, which marks the beginning of the Islamic month of Shawwal.
According to the data, the position of the hilal on 29 Ramadan 1447 Hijriah, or 19 March 2026, is estimated not to meet the visibility criteria used by MABIMS member countries (Ministers of Religion of Brunei, Indonesia, Malaysia, and Singapore).
MABIMS criteria establish that the beginning of an Islamic month can be determined if the hilal altitude is at least 3 degrees and the elongation is at least 6.4 degrees at sunset.
If the hilal position does not meet these criteria, the month of Ramadan is typically completed with 30 days, with the beginning of Shawwal falling on 21 March 2026.
BMKG’s astronomical data serves as one of the scientific references in the process of determining the beginning of Islamic months in Indonesia.
In universal time, this event occurs at 01.23.23 UT, or 09.23.23 WITA (Central Indonesian Time) and 10.23.23 WIT (Eastern Indonesian Time).
At this time, the ecliptic longitude value of the Sun and Moon is recorded as 358.45 degrees.
BMKG also notes that the lunar synodic period—the time interval between the previous conjunction (beginning of Ramadan 1447 H) and the next conjunction (beginning of Shawwal 1447 H)—lasts 29 days, 13 hours, and 22 minutes.
Meanwhile, on the same date, the time of sunset in Indonesia varies. The earliest sunset is estimated to occur at 17.48.13 WIT in Waris, Papua, whilst the latest occurs at 18.49.39 WIB (Western Indonesian Time) in Banda Aceh, Aceh.
Since the conjunction occurs before sunset throughout all regions of Indonesia on 19 March 2026, astronomically, hilal observation to determine the beginning of Shawwal can be conducted after sunset on that day.
BMKG’s astronomical data shows the position of the hilal at sunset on 19 March 2026 to be relatively low. This condition limits the likelihood of the hilal being visible in parts of Indonesia and remains dependent on the results of rukyatul hilal (crescent sighting).