1) Month of the Coptic calendar 
Koiak /ˈkʰɔjæk/ (Coptic: {Coptic|Ⲕⲟⲓⲁⲕ} Koiak /ˈkɔjak/ or {Coptic|Ⲕⲓⲁϩⲕ} Kiahk /ˈkijaxk/), is the fourth month of the Coptic calendar. It lies between December 10 and January 8 of the Gregorian calendar. The month of Koiak is also the fourth month of the Season of Akhet (Inundation) in Ancient Egypt, when the Nile floods ...