Guru Nanak, also referred to as Baba Nanak, was the founder of Sikhism and is the first of the ten Sikh Gurus. These Gurus were responsible for shaping the beliefs of the Sikhs.
Guru Naka’s birthday, which is one of the most important festivals in the Sikh calendar, is commemorated on the Full Moon Day (Pooranmashi or Purnima) of the Lunar Month Kartik. The celebrations usually commence with Prabhat Pheris, which are early morning processions, that begin at the Gurudwaras (a place of assembly and worship for Sikhs) and proceed around the localities singing hymns.
Celebrations begin early in the morning at about 4am-to 5am. The day starts with the singing of Asaa-Ki-Vaar (morning hymns), followed by combination of Katha (exposition of the scripture) and Kirtan (hymns from the Sikh scriptures). This is followed by the Langar, a special community lunch, which is arranged at the Gurudwaras by volunteers. A free communal lunch that everyone, irrespective of gender, caste, class or creed, be offered food in the spirit of seva (service) and bhakti (devotion).
Night prayer sessions are also held in some Gurudwaras, which begin around sunset when Rehras (evening prayer) is recited, followed by Kirtan until late at night.