When Is Eid al-Fitr 2026? BMKG's Prediction on the Crescent Moon Determining 1 Shawwal
The Ministry of Religion will hold an isbat session to determine 1 Shawwal 1447 H (Eid al-Fitr) on 19 March 2026. The crescent moon’s position prediction can be viewed from the “Crescent Moon Forecast Information Document for Sunset on 19 March 2026 Determining the Start of Shawwal 1447 H”, downloaded from the official BMKG website on Monday, 9 March 2026. BMKG noted that 19 March 2026 will be the time of conjunction.
“Geocentric conjunction or ijtima’ is an event when the ecliptic longitude of the moon equals the ecliptic longitude of the sun as if observed from Earth’s centre. This event will occur again on Thursday, 19 March 2026 at 01:23:23 UT, or Thursday, 19 March 2026 at 08:23:23 WIB, or Thursday, 19 March 2026 at 09:23:23 WITA, or Thursday, 19 March 2026 at 10:23:23 WIT,” according to BMKG.
BMKG stated the synodic period of the moon since the previous conjunction until the forthcoming conjunction is 19 days, 13 hours and 22 minutes. BMKG noted that the conjunction occurs before sunset on 19 March across all Indonesian regions.
“Astronomically, the implementation of crescent moon observation (rukyat) to determine the start of Shawwal 1447 H for those applying rukyat in their determination is after sunset on 19 March 2026,” BMKG stated.
Crescent Moon Height Forecast for 19 March 2026
The height of the crescent moon is the angle expressed from the position of the moon’s projection on the observed horizon to the position of the moon’s disc centre. The crescent moon height in Indonesia at sunset on 19 March 2026 ranges from 0.91 degrees in Merauke, Papua to 3.13 degrees in Sabang, Aceh.
Elongation
Elongation is the angular distance between the centre of the moon’s disc and the centre of the sun’s disc as observed by an observer on Earth’s surface. The geocentric elongation in Indonesia at sunset on 19 March 2026 ranges from 4.54 degrees in Waris, Papua to 6.1 degrees in Banda Aceh, Aceh.
Moon Age
Moon age is the time difference between sunset and the time of conjunction. The moon age in Indonesia at sunset on 19 March 2026 ranges from 7.41 hours in Waris, Papua to 10.44 hours in Banda Aceh, Aceh.
Additionally, BMKG also noted there is potential for other astronomical objects during the moon observation on 19 March. BMKG mentioned that from sunset until moonset, Saturn will be present with an angular distance of less than 10 degrees from the moon.
Determination of Eid al-Fitr
The determination of the start of Shawwal in Indonesia is conducted through an isbat session held by the Ministry of Religion. The Ministry has scheduled the isbat session for determining Eid 2026 on 19 March.
The isbat session involves broad representation of the Islamic community, ranging from Islamic organisations such as NU, Muhammadiyah, PERSIS, Al-Irsyad Al-Islamiyyah, Hidayatullah, and the Federation of Islamic Community (PUI), to experts in Islamic astronomy and astronomy from various institutions, including BMKG, BRIN, Planetarium, and astronomical observatories.
Indonesia applies the standard or criteria agreed upon by the Ministers of Religion of Brunei Darussalam, Indonesia, Malaysia, and Singapore (MABIMS) in determining the crescent moon. According to the Ministry of Religion website, the new MABIMS criteria stipulate that imkanur rukyat is considered to meet requirements if the crescent moon height reaches 3 degrees with an elongation angle of 6.4 degrees.