Gurpurabs

The word joins Guru with purab, a festival. Bhai Gurdas uses it in his Vars, which shows it was already known in the time of the Gurus. The dates of the first four Gurus' passing were entered on a leaf in the first volume of the scripture, according to the Encyclopaedia of Sikhism.

The most widely observed include the birthdays of Sri Guru Nanak Dev Ji and Sri Guru Gobind Singh Ji, the martyrdom days of Sri Guru Arjun Dev Ji and Sri Guru Tegh Bahadur Ji, and the first installation of the scripture at Harmandir Sahib, on 16 August 1604. Vaisakhi and the martyrdom days of the Sahibzade are observed with them.[EoS][Web]

The SGPC says birthday celebrations usually last three days. An akhand path, an unbroken reading lasting about forty-eight hours, comes first. A day before the Gurpurab, a nagar kirtan, or street procession, moves through the town, led by five Sikhs as Panj Piare with Sri Guru Granth Sahib Ji on a palanquin. Singers, school groups and gatka teams follow.

On the day itself, services start early with Asa ki Var, followed by kirtan, talks and sometimes amrit ceremonies. Ardas, kara prashad and langar complete it. Large anniversaries have been marked on a major scale in recent times, such as 1967 for the tercentenary of Sri Guru Gobind Singh Ji's birth and 1969 for the 500th anniversary of Sri Guru Nanak Dev Ji's.[Web][EoS][EoS]

Many dates were recorded in the lunar Bikrami calendar. A lunar month has two halves, vadi (the dark half) and sudi (the bright half). Because lunar months do not keep step with the solar year, a lunar date moves against the Common Era calendar each year. Sri Guru Gobind Singh Ji's birth is given as Poh sudi 7, which the SGPC equates with 22 December 1666. The SGPC also publishes a Nanakshahi calendar and a yearly list of dates.[EoS][Web]