The full-moon day of the fourth month, Kattika, usually found in the phrase Komudī Catumāsinī.
The Commentary (DA.i.139) says it was so called because then the white water-lily flowered luxuriantly (kumudāni supupphitāni honti).
Vin.i.155, 176f; D.i.47; M.iii.79, 80; DhA.iii.461; J.v.262, etc.