The year 2015 is Saka era 1936-1937 in the Hindu calendar. The Hindu calendar runs from A.D. 78, with the year commencing on March 22, or March 21 in leap years.
The Hindu calendar was first introduced by the Indian government in 1957 to provide a unifying calendar for the whole of India. The Hindu calendar year runs for 12 months, and is tied to lunar months of approximately 29 1/2 days, covering 354 days of the year. A leap year happens every 3 years, creating an extra month to account for the 11-day shortfall in each regular calendar year.