Why do we celebrate guru nanak dev ji's gurpurab in November?

Guru Nanak Dev Ji's Gurpurab is celebrated in November to commemorate his birth, which is traditionally observed on the full moon day of Kartik month in the Sikh calendar, usually falling in late October or November. This occasion honors the teachings and contributions of Guru Nanak, the founder of Sikhism, who emphasized the values of equality, service, and devotion to God. Celebrations include prayers, singing of hymns, and community service, reflecting his message of harmony and compassion.