Jantri 500 (Sikh calendar tables)

Pal Singh Purewal's Jantri 500 Years and his subsequent design of the Nanakshahi calendar represent decades of his own calendrical research into Sikh dating conventions, adopted formally by the Shiromani Gurdwara Parbandhak Committee in 2003 as an attempt to fix gurpurab dates to the solar tropical year rather than the older lunar-solar Bikrami system. That adoption was not the end of the story: the Nanakshahi calendar Purewal designed became genuinely contested within the Sikh community, and the SGPC amended it in 2010 in ways that partially reintroduced Bikrami-based dating for some events, a compromise some traditionalists and some reform advocates both criticized from opposite directions. Purewal's own calendrical scholarship is respected as careful and well researched; the calendar's practical adoption remains an unresolved point of community disagreement rather than a settled standard.