Adhika-masa
Adhika-māsa (Sanskrit: अधिकमास, romanized: Adhikamāsa), also called the Adhik-mas, Mala-māsa, and the Purushottama-māsa, is an intercalated month in the Hindu calendar that is inserted to keep the lunar calendar aligned with the months of the year. The adhika-masa is an extra lunar month added to the solar calendar every three years so that the lunar and the solar years are synchronised, along with the agricultural cycle and seasons.