The word Guru is derived from two words, ‘Gu’ and ‘Ru’. The Sanskrit root “Gu” means darkness or ignorance. “Ru” denotes the remover of that darkness. Therefore one who removes darkness of our ignorance is a Guru. Gurus are believed by many to be the most necessary part of lives. On this day, disciples offer puja (worship) or pay respect to their Guru (Spiritual Guide). It falls on the day of full moon, Purnima, in the month of Ashadh (June–July) of the Shaka Samvat, Indian national calendar and Hindu calendar.