Nepali date converter

What the Bikram Sambat calendar is

Bikram Sambat, BS, is Nepal's official calendar. It runs roughly 56 to 57 years ahead of the Gregorian calendar, AD, and is used for almost everything domestic: birth certificates, land records, school and university sessions, and most government paperwork, while AD stays the norm for banking and anything shared internationally. The two calendars run side by side in daily life in Nepal, which is why converting between them accurately matters rather than being a curiosity.

Why Bikram Sambat months are not a fixed length

The Gregorian calendar fixes each month's length in advance, with only February varying by a leap year rule anyone can compute. Bikram Sambat does not work that way. It is a solar calendar based on when the sun crosses into each sign of the sidereal zodiac, so a month can run anywhere from 29 to 32 days, and the exact count for a given month in a given year is set by Nepal's official calendar rather than derived from a formula. A converter built on a fixed 30 or 31 day assumption drifts out of alignment within a few years. This tool works from a checked, year by year reference table instead, covering 2000 to 2090 BS, roughly 1943 to 2034 AD.

How to use this calculator, step by step

1. Pick a tab: Convert for a single date, Difference for the gap between two dates, Age for someone's age, or Add or subtract for a date a set length of time before or after another one.
2. For each date field, choose BS or AD depending on which calendar you already have the date in.
3. Pick the year, month and day from the dropdowns, in either calendar. The month name always spells out which calendar you are in, so there is no risk of mixing up month and day.
4. Read the result card. Convert and Add or subtract show both calendars side by side plus the day of the week and Nepal's fiscal year. Difference and Age show a calendar aware years, months, days breakdown in both systems, since they do not always agree on the day count.
5. On the Add or subtract tab, set a direction, an amount and a unit, and watch the result update as you change any of them.

Nepal's fiscal year, explained

Nepal's government and most businesses run their financial year from Shrawan 1 to the last day of Asar, which lines up with roughly mid July to mid July on the Gregorian calendar rather than January to December. Tax deadlines, government contracts and budget reporting are usually quoted against this fiscal year rather than the calendar year, so a date in Chaitra and a date three months later in Shrawan actually fall in two different fiscal years, even though they read as adjacent months. Every result on the Convert and Add or subtract tabs shows which fiscal year a date falls into, its position in that year, and how many days remain in it, since that framing is often the one that actually matters for money or government paperwork in Nepal, and it is not something most date converters surface at all.

Add or subtract days, weeks, months or years from a date, in either calendar

Most date converters only go one way: convert a single date, or find the gap between two dates you already have. A lot of real situations start from the opposite direction, a start date and a length of time, and need the date at the other end. A 90 day tender validity, a 35 day public notice period, a one year work permit, a loan tenure quoted in months, an apprenticeship or probation period, a government deadline counted a fixed number of days after a filing date: all of these are, underneath, the same question, what date do you land on if you add a set amount of time to a given date. Doing that by hand in the Bikram Sambat calendar means tracking exactly which months in exactly which years run 29, 30, 31 or 32 days, which is the kind of detail a flat 30 days a month estimate gets wrong within a few cycles.

The Add or subtract tab is built for that gap, and your start date does not have to be in Bikram Sambat to use it. Pick a start date in either calendar, a direction, an amount and a unit, days, weeks, months or years, and it works out the exact date on the other end using the real Bikram Sambat month lengths for the years involved, not an approximation. That last part holds even when you start from a Gregorian date: a step of months or years is always counted in real BS calendar months, so the Gregorian result you get back can land a day or two away from what counting plain 30 or 31 day Gregorian months would have given, and that difference is the point rather than a rounding error, since it is what makes the result correct for a term that is actually quoted in Bikram Sambat even if you happened to type the start date in AD. Adding or subtracting months or years keeps the same day of the month wherever that day exists in the target month, and moves back to the last real day of that month on the years it does not, a fairly common outcome given how much BS month lengths vary, with a note telling you when that adjustment happened. Days and weeks always count exact calendar days regardless of month boundaries. The result shows the date in both calendars, its day of the week, and the Nepali fiscal year it falls into, so a single calculation answers all three questions a deadline usually raises at once.

Two worked examples

Someone born on Baisakh 15, 2060 reaches Bhadra 24, 2083 at an age of 23 years, 3 months and 9 days by the Bikram Sambat calendar, and 23 years, 3 months and 11 days by the Gregorian calendar, for the exact same pair of dates. The years and months agree; the days differ by two, simply because Bikram Sambat and Gregorian months are not the same length, not because either figure is wrong.

A 90 day period starting on Shrawan 1, 2083, the first day of that fiscal year, lands on Aswin 29, 2083, which is October 15, 2026 on the Gregorian calendar, a Thursday. That is the kind of figure the Add or subtract tab is built for: a loan tenure, a legal notice period or a visa validity window quoted in Bikram Sambat, worked out exactly rather than estimated at 30 days a month.