Guru Nanak Dev Ji's Date of Birth
So much has been written about Guru Nanak Dev Ji's birth date that it seems wholly unnecessary to write yet another article about the subject. I almost decided against it but deemed it necessary given the purpose of this website and the lack of clarity and balance in other pieces I've read.
Guru Nanak Dev Ji's birth date is celebrated on Kartik Puranmashi in the Bikrami calendar, which usually falls in the month of November. This date is cited in many historic Sikh texts such as Bansavlinama, Gurpartap Suraj Granth, and Panth Parkash. All these texts have a single source for the date of Kartik Puranmasi, which is the Bhai Bala Janamsakhi. But modern Sikh historians have significant doubt that Bhai Bala ever existed. They believe the Janamsakhi to be a product of the Hindalia sect which was adversarial towards the mainstream Sikh panth and held Baba Hundal in higher regard than Guru Nanak Dev Ji himself.
Others believe the date of Kartik Puranmashi is mentioned by Bhai Gurdas in his Kabit 345. Here is the first line of Kabit 345 with translation:
ਕਾਰਤਕ ਮਾਸ ਰੁਤਿ ਸਰਦ ਪੂਰਨਮਾਸੀ ਆਠ ਜਾਮ ਸਾਠਿ ਘਰੀ ਆਜੁ ਤੇਰੀ ਬਾਰੀ ਹੈ ।
"It is the month of Kartik, the cool season. On the day of the full moon, the day of eight watches and sixty periods, it is your turn"
Although the Kabit mentions Kartik Puranmashi it does not mention Guru Nanak by name. Nevertheless, some Sikhs interpret the couplet as referring to his birth.
Modern historians generally believe that the more accurate date of Guru Nanak Dev Ji's birth is Baisakh 1, 1526 which is converted to March 27, 1469 in the Julian calendar or Vaisakhi in the Nanakshahi calendar. Unlike the single source for the Kartik Puranmasi date, there are multiple sources for the month of Baisakh. Among them are the Puratan Janamsakhi, Sodhi Meherban Janamsakhi, and Gian Ratnavali. But even the date of Baisakh 1, 1526 was arrived at using a calculation. By subtracting the years, months, and days Guru Nanak lived (70y, 5m, 7d) from the known date that he died (Asu 8, 1596), you get Baisakh 1, 1526. If the exact length of his life is inaccurate, the date is inaccurate as well.
If all this sounds very confusing, that's because time keeping and calendars are imperfect. If you are celebrating Guru Nanak Dev Ji's Gurpurab, in all likelihood it will be on Kartik Puranmashi sometime in November. In fact the Mool Nanakshahi Calendar which was created in 2003 still uses Kartik Puranmashi from the Bikrami calendar because this date is so deeply entrenched amongst Sikhs. This is perfectly fine as its a tradition going back hundreds of years. If you choose to celebrate it at home on Vaisakhi, that's fine too. Just be sure to make a distinction between the celebration of the founding of the Khalsa in 1699 and the birth anniversary of Guru Nanak Dev Ji in 1469 or your kids might get confused.
Guru Nanak Dev Ji would have had a good laugh hearing all the controversy surrounding his birth date and would encourage us to see each day as any other. So whether you celebrate on Kartik Puranmashi or Vaisakhi, celebrate his birth by doing something to honor his teachings.