As the majority of the Arab and Muslim world prepares to celebrate Eid Al Adha on Wednesday, May 27, 2026, four countries—India, Bangladesh, Brunei, and South Africa—will observe the holiday a day later, on Thursday, May 28. This decision is based on the differing moon-sighting determinations for the start of Dhul Hijjah. Official religious authorities in these countries confirmed that the first day of Dhul Hijjah began on May 19, leading to Arafat Day on May 27 and Eid Al Adha on May 28. The variation in celebration dates is attributed to the longstanding differences in moon-sighting practices, with each nation relying on its own methods of observation and astronomical calculations. In contrast, over 28 Arab and Islamic countries, along with Muslim communities in Western nations, will follow Saudi Arabia's moon sighting and celebrate Eid on May 27. Astronomers note that such discrepancies are common due to varying geographical conditions and the reliance on either naked-eye sightings or astronomical calculations.