The Birthday of Guru Nanak Dev Sahib, also known as Guru Nanak Gurpurab, celebrates the birth of the founder of Sikhism and the first of the ten Sikh Gurus. It usually falls in November and is one of the most important festivals in the Sikh calendar. The day is marked with prayers, singing of hymns, processions, and community service, honoring Guru Nanak’s teachings of equality, compassion, and devotion to one God.