Bikram Sambat (Devanagari: विक्रम सम्बत, abbreviated BS) is the official solar calendar of Nepal. It is named after the legendary Indian king Vikramaditya and pre-dates the Gregorian (AD) calendar by approximately 56 years and 8 months. While much of the world organises civic life by AD, Nepalis schedule their fiscal year, school terms, government deadlines, festivals and much of daily life by BS.

How the calendar is structured

The Bikram Sambat calendar has 12 months, but unlike the Gregorian calendar, the months are not of fixed length. Each month can be 29, 30, 31 or 32 days long, depending on the solar position calculated by Nepal's Calendar Determination Committee. The new year begins on 1 Baisakh, which falls in mid-April of the Gregorian calendar.

The twelve Nepali months

In order, the months are: Baisakh, Jestha, Ashadh, Shrawan, Bhadra, Ashwin, Kartik, Mangsir, Poush, Magh, Falgun, and Chaitra. Each has a Nepali script form too — बैशाख, जेठ, असार, साउन, भदौ, असोज, कार्तिक, मंसिर, पुस, माघ, फाल्गुन, चैत.

Why is Nepal still on BS?

Nepal officially adopted Bikram Sambat as its national calendar in 1903 AD (1960 BS). Unlike India, which reverted to Gregorian for civic use, Nepal kept BS in administrative and ceremonial roles. This is partly due to its astronomical accuracy (it is a sidereal solar calendar), and partly due to cultural identity.

Common conversion confusion

Many newcomers assume that adding 56 or 57 to an AD year always gives the correct BS year — this is only roughly correct. Because the BS new year falls in mid-April, dates between January and mid-April have a different offset than dates after mid-April. For example, 1 January 2026 AD is 17 Poush 2082 BS, not 2083 BS. Use a real AD to BS converter rather than naive year arithmetic.

Where you'll see BS in daily life

Citizenship cards, passports, school certificates, government tenders, and tax filings in Nepal all use BS dates. Knowing how to convert quickly between the two systems is a practical necessity.