Building an Open-Source Nanakshahi Calendar: Identity and a Spiritual and Computational Journey

Until the late twentieth century, Sikhs continued to use multiple calendars, mostly the Bikrami calendar, for determining dates for important Sikh events. The Bikrami calendar is longer than the tropical year and has issues such as a shifting relationship with seasons. Pal Singh Purewal proposed the Nanakshahi calendar in 1992. It was adopted by the Shiromani Gurdwara Prabandhak Committee (SGPC) in 1998, but has since diverged from the original proposal and its intent. As the debate about Sikhs observing their community occasions according to the “reformed” Nanakshahi Calendar or “mool” Nanakshahi calendar continues, the difference is not apparent to many Sikhs. This paper explores the questions, research, and workings of the original(ਮੂਲ) Nanakshahi calendar. An open-source programming library was built to encourage the adoption of the Nanakshahi calendar in software. Further, this paper proposes new terms based on Gurbani and Panjabi language etymology that were left open in the original Nanakshahi calendar.