There are sixteen kalas (phases) of the Moon. Out of these sixteen, only fifteen are visible. The sixteenth is said to be beyond our visibility.

1. Amrita
2. Manada
3. Poosha
4. Tusthi
5. Pusthi
6. Rati
7. Dhruti
8. Sasichini
9. Chandrika
10. Kanta
11. Jyostna
12. Shree
13. Preeti
14. Angada
15. Poorna
16. Poornamruta

These sixteen kalas are ruled by the sixteen Nitya Devis and are called the Shodasa Nityas.