The traditional Chinese lunar calendar divides the year into 24 solar terms. Start of Spring (Chinese: 立春), the first solar term of the year, begins this year on Feb 4 and ends on Feb 17. Start of Spring lifts the curtain of spring. After that everything turns green and full of vigor; people clearly see that the daytime is becoming longer and the weather is becoming warmer. Here are nine things you should know about Start of Spring. Start of Spring and Spring Festival As a solar term, Start of Spring had already entered people's lives in the Spring and Autumn Period (770-476 BC). At that time, there were eight solar terms. According to some experts, the 24 solar terms were used for the first time in books during the Western Han Dynasty (206 BC-AD 24), when the Start of Spring was set as the Spring Festival. In 1913, the first day of the first month of the lunar year was mandated as the Spring Festival.