Jakarta, May 23 -- The Hajj pilgrimage can be considered the most complex religious event in the world, involving millions of Muslims from across the globe congregating in a confined area over a short period.

This year, over 1.83 million Muslims are expected to perform Hajj worship simultaneously at the Great Mosque of Mecca (Masjid al-Haram), Arafat, Muzdalifah, and Mina in Saudi Arabia.

The challenge lies in the fact that core Hajj rituals are only considered valid when performed at specific times and locations.

Tawaf, or circling the Kaaba seven times counterclockwise, must be done at the Great Mosque; wukuf, or standing at Arafat, must occur from noon to sunset; and sa'i, or walking seven times between Safa and Marwa hills, is also...