The calendar year of Islam begins not with the birthday of our prophet (peace be upon him) not from the time that the revelation came to him (Bethat) nor from the time of his ascension to heaven, but with the migration (Hijra) from an undesirable environment into a desirable place to fulfill Allah's command. It was migration from a plot that was set by the leaders of the Quraysh who were plotting to kill prophet Muhammad, and to destroy the truth that today is being conveyed to mankind everywhere against tyranny and injustice. Their purpose was to destroy the foundation of the Islamic state, the Sunnah of the tradition of the prophet, and to prevent the revelation being delivered by Allah's messenger to mankind.
The Islamic calendar is reckoned from the time of migration (Hijra) of Prophet Mohammad (Peace Be Upon Him) from Mecca to Madina. The Prophet's decision to migrate from Mecca came after several years of inhuman treatment of the faithful by the powerful tribes who were united despite all their feuds to stop the spread of Islam.
Prophet Mohammad's decision to leave Mecca coincided with the infidel's plan to assassinate him. In 622 AD, the Quresh tribesmen held a meeting and decided that a band of young men, one from each tribe, should assassinate Prophet Mohammad collectively so that their responsibility for the murder could not be placed on any particular tribe.
On the eventful night, the Prophet asked his cousin Ali Ben Abutalib to take his place in bed to make the Meccans think that he was asleep. The Prophet himself slipped out unobserved alongwith his loyal follower Abu Bakr (who was chosen as the first C aliph after the death of the prophet). They secretly made their way to a cave named Thawr, not far from Mecca and lay in hiding there for a day or two until Abu Bakr's son reported that the search for him had been given up. Then the two set out from Madina on camel back. They reached Quba, on the edge of the Madina oasis, on 12th Rabiul Awwal. With Mohammad's arrival in Quba a new phase of his career and glory of Islam started.
This migration has a special significance in the history of Islam. It ended the Meccan period of humiliation and torture and began the era of success. His own people to whom he preached Islam for 13 years neglected the Prophet of Islam. But he was cordially received in Madina as an honored chief.
In Madina his power enhanced day by day. Here he was not only the religious leader but took the role of a politician and statesman too. Prophet Mohammad expired ten years after his migration to Madina but only in one decade he changed the course of human history.
In view of this special significance of the Prophet's migration the consultative body advised the Second Islamic Caliph, Omar ben Khattab, to start the Islamic year from the date of migration of the Prophet from Mecca to Madina.
According to early Moslem scholars, Abu Musa Al Shari drew attention of Omar to an improperly dated debenture or IOU which was payable in the month of Shaban but it was not clear which Shaban was actually meant, the present one or the coming one. Omar called the dignitaries for consultation who made several suggestions to begin the Islamic calendar.
Ali (who later became the fourth caliph) suggested the Hijra as the beginning of the Islamic year with Moharram as its first month. Consequently, Caliph Omar in 21 A.H. or 641 A.D introduced the Islamic calendar in its present form.
QURANIC GUIDANCE
The guidance about the Islamic calendar is taken from the following verses from the Holy Quran: (In the name of GOD most gracious and most merciful)
"Lo the number of the months with God is twelve months." IX:36.
"They ask thee, of new moons. Say: They are fixed seasons for mankind and for the pilgrimage." II:189.
"He it is who appointed the sun a splendor and the moon a light, and measured for her stages, that ye might know the number of the years, and the reckoning." X:5
The Islamic Calendar of 12 Lunar Months is determined by observation of the new moon with no effort by intercalation (addition) or other means to synchronize the Lunar year with the Solar year.
Life Of The Final Messenger - Muhammad pbuh (Seerah) - 12 Hijrah (Migration) - Mufti Ismail Menk
https://www.youtube.com/watch?v=j33p--TzvuI24 - The Migration of The Prophet - The Prophetic Life in Focus - Sh. Abdul-Rahim Reasat
https://www.youtube.com/watch?v=HyrtOCElQY4From Preaching Against Islam to Becoming a Muslim!
https://www.youtube.com/watch?v=HVAaoz0pGdsAsking Japanese Muslims Why They Converted To Islam
https://www.youtube.com/watch?v=MIj2rtL2_bsLessons Learnt from the Leadership of Prophet Muhammad (pbuh) in Uniting the Muslim Ummah - Dr Zakir Naik
https://www.youtube.com/watch?v=C47PVxMpOrw
Topic: Lights on the way