The answer to that is 21 days exactly, although you need to bear in mind that this can vary, depending on a number of circumstances. Generally speaking however, fertile chicken eggs which are hatched out by a hen will take 21 days before you see little faces staring at you from underneath their mamma's wings.
In linguistics, a register is a variety of a language used for a particular purpose or in a particular social setting.
compute - make a mathematical calculation or computation. calculate, cipher, cypher, figure, reckon, work out. math, mathematics, maths - a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement.