BS vs AD: the differences every Nepali should know
Bikram Sambat and the Gregorian calendar use different epochs, different month systems, and different new-year days. Here's exactly how they differ.
October 1, 2025 · 4 min read
Different epochs
Bikram Sambat counts years from 57 BCE; the Gregorian calendar counts from the traditional birth of Christ. The result: BS is roughly 56 years and 8 months ahead of AD — never behind.
Different new-year day
BS new year falls on 1 Baisakh, which lands in mid-April of AD. So when AD ticks over from 31 December to 1 January, no BS year change occurs.
Different month lengths
Gregorian months have fixed lengths (28, 30 or 31 days, with February occasionally getting 29). BS months can be 29, 30, 31 or 32 days, and the lengths vary year to year.
Same week, same days
Both calendars share the same seven-day week. Sunday is आइतबार, Monday is सोमबार, and so on. This is why BS-AD converters can give you the day of the week reliably for either system.
When to use which
In Nepal, BS dominates official documents (citizenship, passport, school papers, tax returns, government deadlines). AD is standard for international communications, banking with foreign institutions, and most online services. Most Nepalis live with both at once.