Generally, according to Panchang or Hindu Calendars, there is one Solar Transition (Surya Sankramana) in each Hindu month. In case of Adhika Masa (Mal Maas, Purushottam Maas), there will be no Solar Transition in that particular month.
And when there are two Surya Sankramana in a lunar month, that month is referred to as Kshaya Masa (Kshaya Masam, Lost Month, Deletory Month). Kshaya Masa occurs very rarely, once in 141 years. And in rarest of rare cases, its occurs once in 19 years.
Kshaya Masa occurs only in one of the three Chandramana Months – Kartika Month, Margashirsha Month or Poush Month. As Sun’s faster motion during this period, there will be two Sankramanas in a lunar month and therefore the duration of Kshaya Masa could be very less than the corresponding lunar month. The lunar year which has Kshaya Masa will have two Adhika Masams, one preceding it and another one following it. And the Kshayamasa does not count by its name.
The last Kshaya Masa was in 1983 and the next coming two Kshaya Masa are in 2124 and 2284.