The first day of Hajj, yaum at-tarwiya, approximately takes place on August 19, 2018, which is the eighth day of the islamic month Dhu l-Hiddscha. Hajj is the great Islamic pilgrimage to Mecca. On the first day of Hajj, which is also known as the day of fetching water and quenching the thirst or the day of the overflowing, the participating Muslims walk from Mecca to Mina.