太陰暦
The 12 animals are also linked to the traditional Chinese agricultural calendar, which runs alongside is better known Lunar calendar. Instead of months, this calendar is divided into 24 two week segments known as "Solar Terms". Each animal is linked to two of these solar terms for a period similar to the Western month. Unlike the 60 year Lunar calendar, which can vary by as much as a month in relation to the Gregorian calendar, the agricultural calendar varies by only one day, beginning on the Gregorian calendar on 3 or 4 February every year. Again unlike the cycle of the lunar years, which begins with the Rat, the agricultural calendar begins with the Tiger as it is the first animal of spring.