Adhik Mass is an extra month in the Hindu calendar that is added periodically to keep the lunar and solar calendars in sync. It is also known as Purushottam Mass and is considered an auspicious time for spiritual practices and self-improvement. Adhik Mass occurs approximately every three years and is added after the month of Ashadh. During this time, Hindus may observe additional fasts, offer special prayers, or engage in acts of charity and kindness.