BIKRAMI SAMMAT: A Calendar named after a Hindu king Vikramaditya. In Punjabi Vikrami is pronounced as Bikrami. Its abbreviation is Bk. The Hindus calculate their dates as per the Hindu astrology. Some ignorant Sikhs too adhere to this calendar. For a Sikh all the calendars have the same significance. During the time of Guru Sahib, Bikrami Sammat was in practice and now Gregorian calendar is used by the whole of the world.
References :
1. The Sikh Reference Book, Dr Harjinder Singh Dilgeer 1997
