The science behind solar, lunar calendars  The Tribune Chandigarh (Oped) 22 January 2014 TRADITIONALLY, Sikh festivals and commemorative days have been ascertained on the basis of the luni-solar Bikrami (or Vikrami) calendar which fixes Hindu festivals. In 1999, the Shiromani Gurdwara Parbandhak Committee (SGPC) tried to introduce a new solar ( continue reading… )