Adhik Maas (Adhika masam) is an extra month which comes in Lunar Hindu Calendar (both – Amavasyant & Purnimant Panchangams) for every 28 to 36 months. In 2012, Adhik month comes as Adhik Bhadrapad month i.e. Bhadrapad month comes twice in 2012 – Adhik & Nija Bhadrapad maasa.
Adhik Bhadrapad month 2012 in North Indian Hindi Calendar: from August 3 to August 31, 2012
Adhika Bhadrapada Maas 2012 in Marathi, Gujarati, Kannada & Telugu calendars: from August 18 to September 16, 2012.
‘Adhika Masa (also called ‘Mala masa and ‘Purshotthama masa) is not followed in Assam, Bengal, Kerala, Orissa and Tamil Nadu since they follow the 365 day calendar.
A lunar year has 354 days while a solar year has 365 days. This means, at the rate of 11 days a year, in the course of 2 years 8 months, the difference is 29 and a half days equal to a lunar month. Therefore every 33rd month is considered an ‘Adhika Masa.