TEMPO.CO, Jakarta - The Islamic Science Research Network (ISRN) corrected that Isha prayer time in Indonesia delayed up to 18-19 minutes averagely than the actual one. Isha is the time to start performing Taraweeh prayer during Ramadan.

“This correction we release is scientific research using Sky Quality Meter (SQM) to calculate the sky brightness and Digital Single Lens Reflex (DSLR) camera to verify it,” said ISRN of Muhammadiyah University head Prof Tono Saksono during an interview in Jakarta, Wednesday, May 8.

Earlier, the astronomy experts also evaluated the Fajr prayer time in the country that was faster by 26 minutes on average than the actual one. While in fact, the beginning time for the Fajr prayer is the start of the time for fasting.

“We have 220 days of observation for Fajr time and 160 days of observation for Isha time since the 2000s and dozens of observation locations since the past 2.5 years,” he added.

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The locations spread in Medan, North Sumatra; Padang and Batusangkar, West Sumatra; Jakarta; Cirebon; Yogyakarta; Balikpapan, East Kalimantan; Bitung, North Sulawesi; Labuan Bajo, East Nusa Tenggara; and Manokwari, West Papua.

The Fajr time in Indonesia should occur when the sun’s depression angle (dip) is at -13.4 degrees, whereas Isha time should begin when the sun’s dip at -11.5 degrees.

“[The government] still refer to a past method used in Egypt that was brought to Southeast Asia including Indonesia, that was -20 degrees and -18 degrees. It has not been corrected yet due to lack of proper tools,” he added.

According to him, the prayer time schedule for 2019 Ramadan issued by Religious Affairs Ministry had yet to be corrected too, and that was based on the past method when no advanced technology available and still relied on the naked eyes.

For example, Fajr time in Jakarta on Wednesday, May 8 was announced at 4:35 and Isha time at 19:00, while the actual ones based on ISRN study was at 5:00:59 and 18:37:19 for Fajr and Isha time respectively.

Meanwhile, for Dhuhr, Asr, and Maghrib time should not have to be corrected, Tono said.

Tono explained his side had reported the problem to the Ministry of Religious Affairs, and that had been taken into consideration. However, there is no follow-up action, such as a decision to date.

ANTARA