The calendar system of Aurii is born from Eraia. The Lylalan Calendar was created before those who would form the northern nations of Aeldun and Dreca left Eraia so it was kept in each of the other nations. There were some variations on the calendar in each splinter nation, but post the Crusades the calendar was standardized as the nations began heavy trade with one another.

Trader’s Day - Callorian Holiday