The month of Muharram is the month of sadness for the Ahl al-Bayt (عليه السلام) and their followers. In this respect, Imam al-Rida (عليه السلام) is reported to have said,

With the beginning of Muharram, my father (عليه السلام) would never smile at all. He would be dominated by depression for ten days. The tenth of this month would be the day of his misfortune, sadness, and weeping. He used to say that on this day Imam al-Husayn (عليه السلام) was slain.