Eid-e-Shuja', also known as Eid-e-Zahra, is the day of Eid for Shia Muslims and marks the end of the mourning period after the events of the Battle of Karbala. It is celebrated on the 9th of Rabi' al-Awwal of the Hijri calendar. Eid is an Arabic word meaning "festivity", and Shuja' means "brave" or "courageous". It stands for "Eid of the brave and courageous companions of Hussein ibn Ali" who fought in the battle of Karbala. Eid-e-Zahra stands for "Eid of the family of Zahra (a.s)", which includes the Prophet Muhammad and the twelve Imams. According to Ulema, this is the day when the heads of the key murderers in the battle of Karbala, Umar ibn Sa'ad and Ubayd-Allah ibn Ziyad, who were killed by Mukhtar, reached Imam Zainul Abedeen and brought a smile on his face. Many Muslims prepare for Eid by applying intricate designs called mehndi to hands and wear bangles, usually each meaning different things. This event doesn't fall on a specific date of the gregorian calendar since Muslims follow the lunar calendar.
The two-month period of Azadari (mourning) reaches its conclusion with the death of the 11th Imam, Imam Hassan Askari on the 8th of Rabi al-Awwal. The day that follows, according to tradition, is the greatest Eid (celebration) for the lovers of the Ahlul Bayt. Also known as Eid-e-Zahra, this day honours the daughter of Muhammad as a day of great joy and happiness for the believers.
One of the events which is marked on this day is the official beginning of the Imamate of the 12th Imam, al-Hujjah ibn al-Hasan. His father, Imam Hasan al-Askari died on the 8th and, immediately after, his son officially took over the mantle of leadership.
The day also marks the first time that the 4th Imam smiled and rejoiced after the events of Kerbala in which he saw his entire family and friends killed by Ibne Ziyaad, Umar ibne Sa’d, Yazid ibne Mu’awiyah and others. It was on 9 Rabi’ul Awwal the year 67 A.H. when Mukhtar sent the head of Ubaydallah Ziyad to Imam Zainul Abedeen who was in Makkah at the time. There are also narrations to point out that this is the day in which The Pious Man Abu LuLu murdered Umar Al-Khattab, the second caliph of the Sunni Muslims, a joyous occasion for Shia Muslims.
Prophet Muhammad(S A ) himself was seen smiling and ‘celebrating’ on this day while in the presence of Imams Ali, Hasan and Husain and said, “It is on this day that Allah will destroy your enemies and the enemies of your grandfather and it is on this day when Allah will accept the actions of your Shi’a and those who love you. This is the day when the words of Allah came true where He said (in the Qur‘an): ‘So those are the houses fallen down because they were unjust.’ (27:52) And this is the day when the Pharaoh (Firawn) of the time of the Ahlul Bayt was destroyed.