The concept of Adhik Maas is unique in the traditional Hindu Lunar Calendars. In 2015 Hindu calendar, there is an extra month or Adhika Maas. In the upcoming year 2015, this extra month will start date from June 17, 2015 and will end on July 16, 2015 as per the North Indian calendar. In the states of Gujarat, Maharashtra, Karnataka and Andhra Pradesh, the Adhik Maas will be observed from the same date i.e. from June 17, 2015 and will end on July 16, 2015. This extra month is dedicated to Shri Krishna.
So in the year 2015, there are thirteen months in the Hindu Lunar calendar. Apart from 12 normal months which are –
There will be an Adhik Shravan maas.
It must be noted that there is no Adhik Maas in the calendars of Assam, West Bengal, Kerala, Orissa and Tamil Nadu as they follow Solar Calendar.
Why Adhik Maas Occurs?
The Hindu calendar is a lunar calendar and it is based on the cycles of the Moon. A lunar month is around 29.5 days long. However, a Solar month is 30 or 31 days long.
The lunar year consists of 354 solar days and solar year consists of 365 days. So, as the years passes by the lunar month starts earlier than the corresponding Solar Month. In both the lunar and solar year there is a difference of 11 days. This difference increases to 29 or 30 days in every upcoming 2 or 3 years and becomes a full month. To compensate and make the two calendars similar an extra month is added in the lunar calendar.