An Adhika Maas is a unique phenomenon associated with Hindu lunar calendars followed in North India, Gujarat, Maharashtra , Andhra Pradesh and Karnataka. Some of Hindu communities avoid auspicious functions like Upanayana, Grah Pravesh or House warming etc during the Adhika Maas period. Here are the auspicious events avoided as per Vaishnava Panchangam followed in Karnataka and Andhra Pradesh.
The auspicious events that are avoided are Chaula, Upanayana, Samavartana, Vivaha, Nutana Griha Pravesha, Purchase of new items (House, Gold etc), Nutana Vrata Arambha, Vrata Udyapana, Shantis like Shashti Poorti Shanti, Tirtha Yatra, Moorti Pratishtapana etc.
The auspicious events that can be performed in Adhika Masa are Garbhadana, Pumsavana, Simanta, Namakarana, Nishkramana (taking the new born to Temple
Vratas started before Adhikamasa can be continued in Adhikamasa.