Nanakshahi calendar designed by Pal Singh Purewal to replace the Bikrami calendar. The epoch of this calendar is the birth of the first Sikh Guru, Nanak Dev in 1469 and the Nanakshahi year commences on 1 Chet. New Year's Day falls annually on what is March 14 in the Gregorian Western calendar. The start of each month is fixed. According to Kapel (2006), the solar accuracy of the Nanakshahi calendar is linked to the Gregorian civil calendar. This is because the Nanaskhahi calendar uses the tropical year instead of using the sidereal year which is used in the Bikrami calendar or the
Adoption of the Gregorian calendar against a horizontal time line. The vertical axis is used for expansion to show separate national names for ease in charting, but otherwise has no significance. Adoption of the Gregorian calendar The adoption of the Gregorian Calendar was an event in the modern history of most nations and societies, marking a change from their traditional (or "old style") dating system to the modern (or "new style") dating system that is widely used around the world today. Some countries adopted the new calendar from 1582, some did not do so before the early twentieth century, and others did so at various