The QingMing Festival （清明節）is also known as Tomb Sweeping Day. It is followed in Chinese cultural areas including Taiwan, China, Hong Kong, Malaysia, Singapore as well as Vietnam. The holiday falls on or around April 5th or the Gregorian calendar.
QingMing is a time when relatives revisit the graves or urns (kept in Buddhist/Taoist temples) of their ancestors. As many outside grave sites may be overgrown with weeds and wild grasses, family members will clear away the mess and make the site neat and clean. Often the wild grasses and shrubs will be burned away. Subsequently, family members will light incense and joss sticks, burn ghost money, pray, and leave offerings of food, flowers, tea, or rice wine.
QingMing has a tradition stretching back more than 2,500 years. Its origin is credited to the TangEmperor Xuanzong in 732. Wealthy citizens in China were reportedly holding too many extravagant and expensive ceremonies to honor of their ancestors every year. Emperor Xuanzong, seeking to curb this practice, declared that respects could be formally paid at ancestors' graves only on QingMing. For example, some sites will have willow branches places in the front of the grave site. It was believed that willow branches kept away evil spirits. In different parts of Asia, QingMing traditions may vary, but generally the concept is the same.
In addition, many families will clean away and pray at their ancestors tombs up to several weeks before the actual day. This helps many avoid crowds and traffic on what can be a very busy day.
In Taiwan, Tomb Sweeping Day is a holiday from work and school. Some years, the holiday is tied to a 3 or 4 day weekend.