Far and away the most important holiday in China is Spring Festival, also known as the Chinese New Year. To the Chinese people it is as important as Christmas to people in the West. The dates for this annual celebration are determined by the lunar calendar rather than the Gregorian calendar, so the timing of the holiday varies from late January to early February.
To the ordinary Chinese, the festival actually begins on the eve of the lunar New Year's Day and ends on the fifth day of the first month of the lunar calendar. But the 15th of the first month, which normally is called the Lantern Festival, means the official end of the Spring Festival in many parts of the country.