Kartika Purnima. The birthday of Guru Nanak (1469), the first Guru, on Kartik's full moon: processions and the Akhand Path. Guru Nanak Gurpurab (Punjabi: ਗੁਰੂ ਨਾਨਕ ਗੁਰਪੁਰਬ (Gurmukhi)), also known as Guru Nanak Prakash Utsav (ਗੁਰੂ ਨਾਨਕ ਪ੍ਰਕਾਸ਼ ਉਤਸਵ) and Guru Nanak Jayanti (ਗੁਰੂ ਨਾਨਕ ਜਯੰਤੀ), celebrates the birth of the first Sikh guru, Guru Nanak. One of the most celebrated and important Sikh gurus and the founder of Sikhism, Guru Nanak is highly revered by the Sikh community. This is one of the most sacred festivals in Sikhism, or Sikhi. The festivities in the Sikh religion revolve around the anniversaries of the 10 Sikh Gurus. These Gurus were responsible for shaping the beliefs of the Sikhs. Their birthdays, known as Gurpurab, are occasions for celebration and prayer among the Sikhs. It is one of three Sikh celebrations still calculated using the traditional Bikrami calendar, alongside Vaisakhi and Bandi Chhor Divas, where as the rest are determined now as per the Nanakshahi calendar. Wiki link Dates computed on the lunar Bikrami calendar as the SGPC keeps it (from New Delhi's sunrise); a day either side is possible. Text: Wikipedia (CC BY-SA).