The believers in the West, at the time of ‘Abdu’l-Baha,
wanted to commemorate His birthday that took place on the same day that the Bab
declared His Mission. ‘Abdu'l-Bahá, however, didn’t approve of this and told
them that this day was not, under any circumstances, to be celebrated as His
day of birth and that it should be exclusively associated with the Bab. But as
the Bahá'ís begged for a day to be celebrated as His, He gave them November
26th, to be observed as the day of the appointment of the Centre of the
Covenant. It was known as Jashn-i-A'zam (The Greatest Festival), because He was
Ghusn-i-A'zam -- the Greatest Branch. In the West it is known as the Day of the
Covenant.
(Adapted from the book, ‘The Centre of the Covenant’ by Hand
of the Cause Balyuzi)