In the Lunar calendar you can find all the Islamic holidays listed. And the last one,
The Gregorian Calendar, is used for marking the international holidays.
Solar Calendar Holidays:
Farvardin 1st – Farvardin 4th : Nowrooz
This holiday marks the beginning of the Persian new year.
On this day Persian families celebrate the first day of spring season and new year by gathering for the cannon shot representing the new year, visiting their relatives and elders and preparing a Haft-Sin.
This tradition also takes place in some other countries.
Some of them are Afghanistan, Kyrgyzstan, Iraq, Kazakhstan, Azerbaijan, Uzbekistan and so on.
Though they celebrate Nowrooz, the date slightly differs in each country (E.g. Iraq: 21st of March).
Farvardin 12th : Islamic Republic Day
Every year, this day is celebrated for marking the Islamic Republic constitution of 1979 which was followed by the overthrow of the Pahlavi dynasty and Mohammad Reza Shah’s exile.
Farvardin 13th : Sizdah-Be-Dar
This date marks the famous 13 Be-Dar festival which is held by picnicking and spending time outdoors with friends and relatives.
Khordad 14th : Demise of Imam Khomeini
On this date, the death of the leader of the Islamic revolution, Ayatollah Ruhollah Khomeini, is grieved publicly.
On June 3rd, Khomeini passed away due to several heart attacks in a short span of time.
Khordad 15th : Khordad 15th Revolt
This date marks the massive riots created by the Iranians as an answer to the arrest of their leader, Ayatollah Khomeini.
though shut down several times, eventually brought about the dethroning and exile of Mohammad Reza Shah and the destruction of the Pahlavi reign.
Bahman 22nd : The revolution of 1979
The 22nd day of Bahman on the Iranian Calendar is the celebrated day of the revolution that changed Iran and its everything to this day.
Esfand 29th : The official nationalization of the oil industry
This law was proposed to Iran’s Legislative Assembly on the 17th of Esfand in the year 1329 and it was accepted by the Senate later on 29th of Esfand.
Lunar Calendar Events:
Muharram 9th : Tasu’a
This day marks many historical happenings such as the infamous Shemr’s breach of Karbala, followed by the preparations for the battle with Imam Huseyn ibn Ali.
This day is followed by another holiday listed below.
Muharram 10th : Ashura
This day marks one of the greatest tragedies in the Shi’a Islam. On this day Imam Huseyn ibn Ali was murdered in Karbala alongside his comrades in arms and the Battle was lost.
Although in Sunni Islam this day is celebrated since it is referred to as the day of atonement (The Liberation of Israelites), in the Shi’a Islam it is still a public mourning.
Safar 20th : Arba’een
Arba’een, also known as Chehelom, is a holiday/Mourning that takes place 40 days after the 10th of Muharram, the day known as Ashura.
This day memorializes the terrible events of Ashura (The death of Imam Huseyn and the 72 men who bravely died alongside him). Many Muslims tend to go to Karbala on this day as a symbol of mourning.
Safar 28th : Demise of Prophet Muhammad and Imam Hassan
Safar 29th or 30th : Imam Reza’s Martyrdom
Rabi’-ul-Awwal 17th : Birth of Muhammad and Imam Jafar
This date is celebrated as the birth date of the grand founder of the Islam religion and the final prophet that existed.
Years later, Imam Jafar, the 6th Imam in Shia Islam was born on the same date.
Jamaad-ath-Thaanee 3rd : Martyrdom of Fatima
This date marks the demise of the daughter of Muhammad the prophet. In her honor , many Shia muslims perform ceremonies that take near 20 days.
Rajab 13th : Imam Ali’s Birth
On this date, Ali ibn Abi Talib, the Prophet Muhammad’s son-in-law was born. The Shia Muslims regard him as their most important religious figure after Muhammad, and in their views, he should have been the one to take after Muhammad.
The Sunni Muslims however, don’t share this view and that is the main reason why Imam Ali was not selected as Muhammad’s successor immediately.
Rajab 27th : The prophet Muhammad’s mission
Muhammad became a prophet of the lord in 610 AC, and he was ordained to “Arise and warn and glorify the Lord”.
This holiday is in the honor of his grace.
Sha’aban 15tyh : Imam Mahdi’s Birth
Muhammad ibn Hasan al-Mahdi, according to the beliefs of Shia Islam, is the last of the Twelve Imams.
He is believed to rise in the apocalypse with Isa-Masih (Jesus Christ), acting as the ultimate saviour of mankind, restoring justice to the world.
Ramadhan 21th : Imam Ali’s Martyrdom
On Ramadan 19th, Imam Ali was attacked while praying by Abd-al-Rahman ibn Muljam.
Though the hit was not extremely fatal, ibn Muljam’s blade was coated with poison and because of this, Imam Ali died on 21st of Ramadan and since then, this day is a public mourning in Iran.
Shawwal 1st and 2nd : Eid ul-Fitr
This holiday marks the end of the holy month of Ramadan during which Muslims fast from sunrise to nightfall every day. Eid al-Fitr has a particular Salat (Islamic prayer) consisting of two Rakats.
Shawwal 25th : Imam Jafar’s Martyrdom
This day marks the demise of the 6th Imam in Shia Islam.
Though it is still not completely known how he died, the most popular theory is that after being arrested a few times by the Abbasid Caliphs, he was eventually poisoned during one of his imprisonments. this day is also a public mourning.
Dh-ul-Hajja 10th : Eid ul-Ghurban
This day is a holiday in honor of Abraham’s willingness to sacrifice his own son upon God’s command which turned out to be a test.
This day is also known as Feast of Sacrifice.
Du-ul-Hajja 18th : Eid-al-Ghadeer
This day is one of the most important holidays in Shia Islam. This is the day in which Ali ibn Abi Talib was announced as the Prophet Muhammad’s successor in a farewell pilgrimage.