Tomb Sweeping Day began in the Tong Dynasty. Buddhist created this festival in reaction to the presence of Christian practices. They perceived that Christians were honoring the dead with their act of the Eucharist celebrating the Risen Christ. In response to the Christians and in order to compete for the attention of the Tong Emperor they created this festival so they could say we have a way of honoring our ancestors too.
For the last three days I have been in Chongqing observing families at the tombs of their ancestors. They bring paper money and burn it. The light fire crackers and bring food and candy. They offer toasts of wine. Each family has their own interesting ways of honoring ancestors. It is very much like All Saints Day that Christians celebrate on November 1.
Many of the traditions are shifting to Spring Break festival due to the costs of gathering with family.
I went to several temples where Buddhist monks practice a more elaborate ceremony. I was not allowed to take photos.