A gurpurab is a Guru's day, and the two largest are the birth of Guru Nanak in November and the birth of Guru Gobind Singh in December or January. The shape is a forty-eight hour akhand path completed on the morning of the day, then a nagar kirtan through the streets: the Guru Granth Sahib on a decorated float, five men in saffron walking ahead of it, volunteers sweeping the road, kirtan on loudspeakers, gatka teams, and stalls giving food to anyone standing on the pavement. In Britain and Canada these processions have become the largest visible Sikh events of the year and require police permits and street closures. Which day any of it falls on is itself contested: the Nanakshahi solar calendar adopted in 2003 fixed the dates, the SGPC amended it back toward the lunar Bikrami reckoning in 2010 under pressure from sant bodies, and factions and diaspora gurdwaras now observe different dates for the same gurpurab. Pal Singh Purewal, who designed the calendar, spent his last years watching it dismantled.