Bikram Sambat (BS or B.S) also spell as Vikram Sambat is the official calendar of Nepal. We are now at 2080 calendar year. This calendar was started by the legendary king Bikramaditya.
Bikram Sambat calendar is a Solar calendar. Bikram Samvat is about 57 years ahead of the solar Gregorian calendar (AD). Our calendar starts with the month of Baishak and marks the beginning of the solar New Year. The last month of BS calendar is Chaitra. Biram Sambat calendar is also called Patro. However. actual Patro is the lunar calendar with Hindu Tithis and Mithis in it.
Source: https://en.wikipedia.org/wiki/Vikram_Samvat