Today is Qingming Jie. To you laowai, it mean Tomb Sweeping Day. This glorious day has a long and famous history just as the glorious history of China. As is known by all Chinese, on this day we clean the tombs to appease our ancestors in the hopes that they won't turn into zombies and eat our brains. It's always scary when that happens.
So, go out and sweep the graves. Make offerings to your ancestors. We don't want more zombies like we had in 1959. It did not help our young communism at the time. Caused many panic across great Chinese motherland. We had to sweep mother's tomb so that she would go back to sleep and not terrorize the proletariat.