ਨਾਨਕਸ਼ਾਹੀ ਕੈਲੰਡਰ 

The Nanakshahi calendar is a tropical solar calendar used in Sikhism. It is based on the "Barah Maha" (Twelve Months), a composition composed by the Sikh gurus reflecting the changes in nature conveyed in the twelve-month cycle of the year. The year begins with the month of Chet, with 1 Chet corresponding to 14 March. The reference epoch of the Nanakshahi calendar is the birth of Guru Nanak Dev, corresponding to the year 1469 CE. Guru Nanak Dev Ji. 

The revised Nanakshahi calendar was 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 14 March 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 old Nanakshahi and Khalsa calendars.

The Nanakshahi calendar is a significant development for Sikhism, as it provides a unified calendar for Sikhs worldwide. It is based on the principles of solar time and is aligned with the Gregorian calendar, making it easy for Sikhs to use in their daily lives.

The 12 months of the Nanakshahi calendar are:

1. Chet (March-April)
2. Vaisakh (April-May)
3. Jeth (May-June)
4. Asadh (June-July)
5. Sawan (July-August)
6. Bhadon (August-September)
7. Pattar (September-October)
8. Katik (October-November)
9. Margashir (November-December)
10. Poh (December-January)
11. Magh (January-February)
12. Phalgun (February-March)

Here are some additional details about the Nanakshahi calendar:

• Leap years: The Nanakshahi calendar has a leap year every four years, similar to the Gregorian calendar. In a leap year, the last month, Phalgun, has 31 days instead of 30.
• Weekdays: The Nanakshahi calendar uses the same weekdays as the Gregorian calendar, with Sunday being the first day of the week.
• Festivals: Many Sikh festivals are celebrated on specific dates in the Nanakshahi calendar. These include Vaisakhi, the Sikh New Year, and Gurpurabs, the birthdays of the Sikh gurus.
• Adoption: The Nanakshahi calendar was officially adopted by the Shiromani Gurdwara Prabhandak Committee (SGPC), the highest Sikh religious authority, in 2003. However, it has not been universally accepted by all Sikhs. Some Sikhs continue to use the Bikrami calendar, which is the traditional calendar used in India.
• Purpose: The Nanakshahi calendar was created in part to address the confusion that arose from the use of different calendars by different Sikh communities. It was also intended to promote Sikh identity and culture.