Guru Nanak Jayanti or Gurpurab is being obsereved by the Sikh community across the nation today. It is the most sacred festival observed by Sikhs worldwide. Gurpurab marks the anniversary of the birth of Guru Nanak Dev, the founder of Sikhism and the first of the 10 Sikh Gurus. The festival is celebrated on a different day each year and it falls on a full moon day, or ‘Kartik Poornima’, in accordance with the Hindu lunar calendar. Celebrations begin a day before the anniversary, with devotees singing hymns and prayers in praise of the guru and organizing processions holding the ‘Nishan Sahib’, or the Sikh flag. During the processions, men perform “Gatka,” a Sikh martial art.