Below is an extract from the book:
“Every year, when the blessed month of Muharram enters, we are reminded of certain incidents: The Hijrah, The Day of Aashura and The Martyrdom of Sayyidina Husain (radhiyallahu anhu). These are generally the topics of discussion in the month of Muharram and Insha-Allah, something will be said in respect to each one.
During the Khilafat of Hazrat Umar (radhiyallahu anhu), Islam had spread far and wide and there was a need to have some kind of date for the correspondence that was being sent out. Hazrat Umar (radhiyallahu anhu) thus consulted with the Sahaaba-e-Kiram as to when the calendar should begin. Different views were presented before Hazrat Umar wisely declared that the calendar begin with the Hijrah.”