Hai (亥) is the twelfth sign of the Earthly Branches. Its animal representation is the Pig or Boar ( 豬).In the continuous sexagenary cycle, every twelfth year corresponds to Hai, and is commonly called "the Year of the Pig" (豬年).There are five types of pig, named after the Chinese elements. In order, they are:Metal, Water, Wood, Fire, and Earth.

nitrogen cycle, carbon cycle, water cycle, and sulfur cycle

A payroll cycle is the determined period of time of allocated hours worked.

reproductive cycle. glucous-insulin cycle. lunar cycle. cellular cycle