What Is the Bikram Sambat Calendar? A Complete Guide
Bikram Sambat (often written BS, B.S., or V.S. for Vikram Samvat) is the official calendar of Nepal. If today is sometime in 2026 by the Gregorian (AD) reckoning, the Bikram Sambat year is roughly 2082 or 2083. The two systems differ by about 56 years and 8 months.
Unlike the purely solar Gregorian calendar, Bikram Sambat is a lunisolar calendar. It tracks both the movement of the sun through the zodiac and the cycles of the moon. That is why the month lengths are not fixed at 30 or 31 days and why the new year lands in mid-April rather than on 1 January.
This guide explains where Bikram Sambat comes from, how its months and years are structured, how it relates to the Gregorian calendar, and why almost every official document, festival, and government notice in Nepal uses it.
Where does the Bikram Sambat calendar come from?
Bikram Sambat is traditionally said to begin in 57 BCE, which is why the BS year stays roughly 57 years ahead of the AD year. Tradition links it to the legendary King Vikramaditya of Ujjain, in present-day India, though historians debate the exact origin. The era spread across South Asia over many centuries.
The calendar was adopted as Nepal's official civil calendar in the early 20th century, during the Rana period. Since then, the Nepali state, schools, banks, and newspapers have used it for all civil dates. India still uses a related Vikram Samvat for many Hindu religious purposes, but Nepal is the one country that runs it as the national administrative calendar.
Why is it lunisolar, not purely solar?
A lunisolar calendar keeps the months tied to the moon while keeping the year tied to the sun. Bikram Sambat months are named for the sun's entry into zodiac signs (sankranti), but the festival and tithi cycle follows the moon. To stop the lunar and solar counts from drifting apart, the system adjusts month lengths, so a month can run anywhere from 29 to 32 days.
How many years ahead is Bikram Sambat of the AD calendar?
Bikram Sambat runs about 56 years and 8 months ahead of the Gregorian (AD) calendar. A common rule of thumb is to add roughly 57 years to a Gregorian year to estimate the BS year. The gap is not a clean 57, because the two new-year points fall on different days.
Because the Bikram Sambat year starts in mid-April, a single Gregorian year overlaps two BS years. From January to mid-April, you add about 56 to the AD year; from mid-April to December, you add about 57. This shifting offset is exactly why a simple subtraction never quite works and why precise conversion needs a lookup table.
A quick offset reference
| Gregorian period | Approximate BS year | Offset to add |
|---|---|---|
| Jan to mid-April | AD + 56 | +56 |
| Mid-April to December | AD + 57 | +57 |
For an exact day-level result rather than just the year, see our step-by-step walkthrough on how to convert BS to AD dates and back.
What are the 12 months of the Bikram Sambat calendar?
The Bikram Sambat year has 12 months, beginning with Baisakh and ending with Chaitra. Each month corresponds to the sun entering a zodiac sign, so the lengths vary year to year between 29 and 32 days. The total still resolves to roughly 365 days, matching the solar year.
| # | Month (BS) | Rough Gregorian span | Typical days |
|---|---|---|---|
| 1 | Baisakh | Apr-May | 30-31 |
| 2 | Jestha | May-Jun | 31-32 |
| 3 | Ashadh | Jun-Jul | 31-32 |
| 4 | Shrawan | Jul-Aug | 31-32 |
| 5 | Bhadra | Aug-Sep | 31-32 |
| 6 | Ashwin | Sep-Oct | 30-31 |
| 7 | Kartik | Oct-Nov | 29-30 |
| 8 | Mangsir | Nov-Dec | 29-30 |
| 9 | Poush | Dec-Jan | 29-30 |
| 10 | Magh | Jan-Feb | 29-30 |
| 11 | Falgun | Feb-Mar | 29-30 |
| 12 | Chaitra | Mar-Apr | 30-31 |
Note that the day counts shift from year to year because they are astronomically determined, not fixed by rule. For a fuller breakdown with the order and meaning of each, read about the 12 Nepali calendar months in order, from Baisakh to Chaitra.
Why does the Bikram Sambat new year fall in April?
The Bikram Sambat new year begins on Baisakh 1, which usually falls around 13 or 14 April in the Gregorian calendar. This day is celebrated as Navavarsha and is a public holiday in Nepal. The date is set by the sun entering the sign of Aries (Mesh Sankranti), not by a fixed Gregorian date.
Because the start point is astronomical, Baisakh 1 can land on 13 or 14 April depending on the year. This solar anchoring is also why the Nepali year does not drift through the seasons the way a purely lunar calendar would. We explain the festival and its timing in detail in Nepali New Year (Navavarsha): why it falls in April.
How is Bikram Sambat different from other Nepali calendars?
Bikram Sambat is Nepal's civil calendar, but it is not the only era used in the country. Nepal Sambat is an older indigenous calendar tied closely to Newar culture and tradition, with its own new year during Tihar. The Gregorian (AD) calendar is used for most international business.
Many Nepalis live with all three at once: BS for official paperwork, AD for global work, and Nepal Sambat for certain cultural observances. The distinctions matter when reading historical dates or planning events. For a side-by-side comparison, see Bikram Sambat vs Nepal Sambat vs AD and their key differences.
Where you will see Bikram Sambat in daily life
Government documents, citizenship cards, and official notices are dated in BS.
School and university academic years follow the BS calendar.
Newspapers, festivals, and religious almanacs (Panchang) use BS and lunar tithis.
Birthdays and anniversaries are often remembered by the BS date, not the AD one.
If you want the daily astrological detail that sits alongside the BS date, our explainer on what Panchang is, with tithi, nakshatra, yoga and karana, covers it. You can also check live dates and conversions in the Nepali Calendar (Katigate) app.
Explore more on Nepali Calendar (Katigate)
Frequently Asked Questions
What year is it in Bikram Sambat right now?
It depends on the month. The Bikram Sambat year runs about 56 years and 8 months ahead of the Gregorian year, so a Gregorian year around 2026 corresponds to roughly BS 2082 to 2083. Because the BS year begins in mid-April, the exact year depends on whether the date falls before or after Baisakh 1.
Is Bikram Sambat the same as the Indian Vikram Samvat?
They share the same origin and era count, both starting around 57 BCE. However, Nepal uses Bikram Sambat as its official civil calendar for all government and daily dates. In India, the related Vikram Samvat is used mainly for Hindu religious and festival timing rather than as the national administrative calendar.
Why do Bikram Sambat months have different numbers of days?
Because Bikram Sambat is lunisolar, month lengths are determined by the sun's movement through the zodiac rather than fixed rules. A month begins when the sun enters a new sign, so it can run from 29 to 32 days. This astronomical anchoring keeps the calendar aligned with the seasons over time.
How do I convert a Bikram Sambat date to AD?
For the year alone, add about 56 to 57 to the AD year, adjusting for whether the date is before or after mid-April. For an exact day, you need a conversion table or app, because month lengths vary. Our detailed guide on converting BS to AD dates walks through the full method step by step.