Among the eternal works and beautiful memorials of Hazrat Ali (MAPH) that will remain significant until the end of Islamic history is the establishment of the Islamic calendar.
During the time of Hazrat Umar (RA), there were differing opinions on setting the date for recording events. Some suggested following the example of the Iranians, who considered the birth or coronation of their king as the starting point of their calendar. Others voted to imitate the Romans. Some believed that the birthdate of the Messenger of Allah (peace be upon him) should mark the beginning of the Islamic calendar.
Hazrat Umar (MAPH) rejected all these suggestions, providing his reasons. Then Hazrat Ali (MAPH) proposed that the year of the Prophet’s (peace be upon him) emigration (Hijra) from Makkah to Medina should be the starting point of the Islamic calendar. Hazrat Umar (MAPH) approved this suggestion, and after gaining the consensus of the Companions, he ordered that the Islamic calendar be based on the Hijra of the Messenger of Allah (peace and blessings of Allah be upon him).
In this way, the Islamic calendar was linked with an event that has its own meaning and significance and fulfills its own mission, and like the calendar of other religions, it is not related to any personality, even to the personality of the Prophet of Islam (PBUH), who is the most prominent human personality and the most beloved of them by Allah and Muslims. Also, it is not dependent on conquests, and expeditions, and its connection with migration is based on deep thought and great philosophy, and in this foundation, there is also an aspect of good news and omen, because it was the beginning and chapter of a new era in human history and human path, and on the other hand, it conveys this message. that clinging to belief and principles, courage, and self-sacrifice are the keys to victory, and the ideological and fundamental aspect always precedes and has priority over the customary and natural aspect.
Affection and sadness of Ali (MAPH) from the martyrdom of Umar (MAPH)
Abu Juhaifa (MAPH) says: I witnessed that Hazrat Ali (MAPH) came after the martyrdom of Hazrat Umar (MAPH) and removed the cloth from his face and said: May Allah’s mercy be upon you, O Abu Hafs! By Allah, now there is no one left after the Messenger of Allah (peace be upon him) except Umar, whom I ask Allah to make my deeds like his deeds.
Also, Hazrat Ali (may Allah be pleased with him) in Nahj al-Balaghah describes Hazrat Umar (may Allah be pleased with him) and says, “What a strange person he was, he straightened crookedness and cured social diseases, He performed the Sunnah of the Prophet (peace be upon him).” He pushed back sedition and chaos; he left the world clean and blameless. He Obeyed Allah, unfortunately he left this world and put the people in different ways now neither the ignorant can find their way in those ways, nor can those who are guided be sure of them.