Tassoua is observed by Muslims on the 9th day of Muharram, the first month of the Islamic calendar, primarily in Iran. This solemn day precedes Ashura and commemorates the final preparations of Imam Hussein and his companions before the Battle of Karbala. Observers engage in acts of charity, participate in remembrance gatherings, and reflect on the profound sacrifices made by Imam Hussein. Typical customs include fasting, prayer, and attending ceremonies that highlight the historical significance of the day. The focus during Tassoua is on spiritual reflection and community support rather than commercial activities. Many individuals and organizations use this time to donate to humanitarian causes and support educational initiatives that embody values of justice and compassion.