Hilal Visibility for Rabi' al-Akhir 1448 H
Will Rabi’ al-Awwal 1448 H last 29 days or 30? Let’s look at the data.
To answer that question, we need to examine the hilal on the evening of 11 September 2026, corresponding to 29 Rabi’ al-Awwal 1448 H. If the hilal doesn’t meet the criteria, the month is extended to 30 days by convention and Rabi’ al-Akhir begins afterward.
Looking at the map first
Section titled “Looking at the map first”
I start with the map because the big picture is immediately clear. No points meet the criteria, while 95 points fail. The best result was at Meulaboh Coast, on the western coast of Aceh. Even there the values fell short.
This map checks many points across Indonesia. So the conclusion isn’t just that one location had poor observations. On that evening, the moon was simply too low and too close to the sun across the entire region examined.
So what happened in the sky?
Section titled “So what happened in the sky?”
The sky chart helps explain the numbers on the map. At Meulaboh Coast, the moon’s altitude was only 1.4°. Its angular distance from the sun (elongation) was just 4.8°.
The Neo MABIMS criteria require a minimum moon altitude of 3.0° and a minimum elongation of 6.4°. Both conditions must be met simultaneously. Since neither was reached, the chart displays a NOT MET status.
As a reminder, the 3° and 6.4° thresholds come from research involving hundreds of hilal observations (see ANTARA and Jurnal Al-Marshad). Below these numbers, the hilal is impossible to see with the naked eye or even with a telescope.
Conditions at the horizon were also unfavorable. The sun set at 18:36, while the moon set at 18:41. The observation window was only about five minutes. The illuminated portion of the moon was just 0.1 percent, making the crescent extremely thin.
Conclusion
Section titled “Conclusion”Based on this data, Rabi’ al-Awwal 1448 H did not meet the Neo MABIMS criteria on the evening of 11 September 2026. Therefore, under these criteria, Rabi’ al-Awwal is extended to 30 days and Rabi’ al-Akhir begins afterward.
This is a visibility calculation result, not an official month-start decision. The official decision follows the rukyah and sidang isbat process by the relevant authorities.
Full data is available through the MABIMS hilal data and hilal visualization.