Guru Nanak was the first of 10 Sikh Gurus, whose divine teachings comprise the Guru Granth Sahib, the Sikh holy scriptures, along with wise hymns from many Hindu and Muslim holy men. According to Their teachings, the Sikhs must carry out their duties to family and society through honest labor, sharing food with others, meditation, and charity. Today, Sikhs around the world celebrate the first Sikh Guru’s life through the Guru Nanak Gurpurab. This sacred holiday occurs every full moon day of Katak, the eighth month in the Nanakshahi calendar. This is thought by many to be the time that Guru Nanak came into this world.