RRI.CO.ID, Jakarta – Ahead of Ramadan, Eid al-Fitr, or Eid al-Adha, Indonesians often look forward to one important moment: the Isbat Session. For some, the term may sound formal, but behind it lies a blend of religious tradition, scientific approach, and a long history of the state’s role in regulating religious life.

The Isbat Session is an official forum organized by the government through the Ministry of Religious Affairs to determine the beginning of Hijri months, such as Ramadan, Shawwal, and Dzulhijjah. This determination serves as the main reference for Muslims in performing their religious duties, while also maintaining uniformity within a diverse society.

In practice, the Isbat Session combines two main methods: hisab and rukyat. Hisab refers to astronomical calculations used to determine the position of the moon mathematically, while rukyat involves direct observation of the hilal, or the first crescent moon, after sunset. The combination reflects an effort to balance modern scientific knowledge with religious traditions.

Historically, the determination of religious holidays has been a concern of the government since the early days of independence. During the administration of Soekarno, the government issued Government Decree No. 2/Um of 1946, which regulated religious holidays, including Eid al-Fitr. Since then, the authority to determine these dates has been entrusted to the Minister of Religious Affairs.

The Isbat Session tradition began to develop in the 1950s as an official mechanism. It was further strengthened during the tenure of Minister of Religious Affairs Saifuddin Zuhri through Ministerial Decree No. 47 of 1963, which laid an important foundation for a more systematic and structured implementation.

Over time, the government also established the Badan Hisab Rukyat (BHR) in 1972 under the Ministry of Religious Affairs. This board is responsible for collecting astronomical data and field observation reports as key considerations in the session. Today, hilal observations are conducted at more than a hundred locations across Indonesia to ensure accuracy.

The Isbat Session is usually held one day before the expected start of a Hijri month, namely on the 29th of Sha’ban or the 29th of Ramadan. The process begins with a presentation of the hilal position by experts, followed by a closed meeting led by the Minister of Religious Affairs and attended by various stakeholders, including Islamic organizations, astronomers, and representatives of state institutions.

Decisions are made based on both hisab calculations and rukyat reports, and are then announced to the public through a press conference. Although it serves as the government’s official reference, the decision is not legally binding for all groups, which is why differences in determining the start of Hijri months still occasionally occur.

Within this dynamic, the Isbat Session functions not only as a forum for determining religious observances, but also as a space for dialogue among diverse religious perspectives. These differences are expected to be approached with mutual respect, reflecting the richness of Islamic traditions in Indonesia.

More than just a formal session, the Isbat Session represents how Indonesia integrates religious values, scientific knowledge, and cultural wisdom into a single mechanism that continues to endure today.