Who made the decision to implement the Nanakshahi Calendar?

Was it was properly debated upon?

In 1994, S. Pal Singh Purewal wrote to the then Jathedar Akal Takht Prof. Manjit Singh in this regard. In 1995. S. Purewal attended a seminar at the Institute of Sikh Studies, Chandigarh, and presented my work on calendars. The Institute then formed a committee comprising scholars from three Universities in the state and other institutes. These scholars thrashed out various ideas and finally submitted a report to the SGPC in 1996. In May [March] 1998, the SGPC General House passed a resolution to implement the calendar.