The Hijri calendar was officially created during the reign of Khalifa Umar ibn al-Khattab. The Prophet's migration or hijra in 622AD marks the beginning of the Hijri year calendar and gives the calendar its name.
The verses recited before Hazrat Umar (R.A) were from Surah Taha or Surah Al-Hadid. After this, Hazrat Umar (R.A) rushed directly to the Holy Prophet (PBUH) with the same sword he had intended to kill him with. However, instead, he accepted Islam.
