Lunar New Year's Day is the first day of the year, according to the traditional lunar calendar. With the adoption of the solar calendar, New Year's Day came to refer to the first day of the solar year. In order to distinguish the two, Lunar New Year's Day is sometimes referred to as Spring Festival. The Lunar New Year is China's most important traditional holiday. However, this holiday is not just one day; rather it encompasses an extended period of time, often lasting until the fifteenth day of the first lunar month.

Legend has it that long ago there was a king named Zu Yi who found it difficult to predict seasonal weather changes and the movement of wind and clouds. He ordered his minister Ah Heng to build an altar and make sacrifices to the deities seeking their assistance. But the deities did not reply. As it happened, a young man named Wan Nian had just invented the sundial and a four-level water clock, which enabled him to accurately predict weather conditions according to the changing seasons. Wan Nian sought out the king and presented him with his inventions. The king was delighted with this development, and ordered Ah Heng to use the new inventions to create a calendar. But when Ah Heng climbed to the top of the Temple of the Sun and Moon, he saw the following poem written by Wan Nian inscribed on the wall:

The sun rises and sets three-hundred and sixty times, circling the horizon to return to its beginning.

Plants wither and flourish over four seasons; twelve moons make up one year's cycle.

When Ah Heng saw this poem, he realized that Wan Nian had already invented the calendar. Fearing that he would fall out of favor if the king learned of this accomplishment, Ah Heng sent an assassin to kill the young inventor. However, his plot was not successful. The king richly rewarded Wan Nian, who exclaimed, "Now the old year has ended and the new year begins; will the king give this auspicious day a name?" Zu Yi replied, "Let it be called Spring Festival."