Year time, which is based on occurred in the two events in the flow of the motion of the earth around the sun is defined. Sometimes, with the spread of spam this sense, the term "year" designates the length of time the circulation of other planets around the Sun, also goes to work.

year, usually to the solar year is said to be. Sometimes a number of lunar-based lunar year equals 12 lunar months, and is more than 10 days from the solar year is shorter.