Tick
From Alter Aeon Wiki
A tick is a unit of time used by the Alter Aeon server to do various housekeeping. Ticks last approximately 29 seconds, and determine when things likes spells run out and areas repop. Each tick advances the in-game time by ten minutes.
Note that tick edges are random, and may range from 15 to 45 seconds, which limits the ability of clients to predict tick edges in advance.
