Crescent Moon Visibility Fails to Meet Criteria, Theoretically Impossible to Sight

The astronomical calculation and moon-sighting team of Indonesia’s Ministry of Religious Affairs has stated that the crescent moon was not visible anywhere across Indonesia on Tuesday, 17 February.

Cecep Nurwendaya, a member of the Ministry of Religious Affairs’ Hisab and Rukyat Body, outlined these findings during a seminar on crescent moon positioning at Hotel Borobudur, Jakarta.

“Across the entire territory of the Republic of Indonesia, the Crescent Moon Visibility or MABIMS Imkan Rukyat criteria were not met,” Cecep said during the seminar.

The MABIMS criteria stipulate a minimum crescent moon altitude of 3 degrees above the horizon at sunset and a minimum elongation (angular distance between the moon and sun) of 6.4 degrees.

Cecep detailed that on the observation date of 17 February, the crescent moon altitude across Indonesian territory ranged from -2° 24’ 43” (-2.41°) to -0° 55’ 41” (-0.93°), whilst the elongation ranged from 0° 56’ 23” (0.94°) to 1° 53’ 36” (1.89°).

Consequently, Cecep explained that the crescent moon heralding the start of Ramadan 1447 H was theoretically predicted to be impossible to sight on this observation day.

“This is because its position was below the horizon at sunset,” he added.

Accordingly, Cecep stated that 1 Ramadan 1447 H, based on astronomical calculations, falls on Thursday, 19 February 2026.

The determination of 1 Ramadan, Syawal, and Zulhijah in Indonesia employs both the rukyat (observation) and hisab (calculation) methods. Hisab serves an informative function, whilst rukyat acts as confirmation of the calculations.

The hisab method uses numerical-mathematical computations to establish the beginning of Hijriah months without factual verification or crescent moon sighting.

Through hisab, Muslims can calculate the geometric positions of celestial bodies to determine scheduling on Earth, including the determination of lunar months associated with worship.

Meanwhile, rukyat is an observation method involving the sighting of the crescent moon with the naked eye or through a telescope.

Indonesia was set to confirm 1 Ramadan following the isbat session, scheduled for 19:05 at Hotel Borobudur, Central Jakarta.