What is the reason of waxing and waning for 15 days of Moon??
Rohinee is one of the 27 stars in Indian astrology, commencing from Ashwinee, Bharanee, Krittikaa, Rohinee etc. They are the daughters of Daksh Prajaapati and the wives of Chandramaa (Moon). Chandramaa was most interested in Rohinee and used to neglect his other 26 wives. So all the 26 daughters of Daksh Jee went to their father and complained about Chandramaa’s special love to Rohinee. Based on their complaint, Daksh Prajaapati gave him Shaap that he shall wane away. When his waning was beyond the reason, those 26 daughters again went to their father. Daksh amended his Shaap that “He will wax for 15 days and wane for another 15 days; and Chandramaa will take holy bath on no-Moon day (Amaavasyaa, or New Moon day), in one of the holy rivers, named Saraswatee (now extinct), in Prabhaas Kshetra (area). After that all 26 daughters stopped interfering with Rohinee and Moon.