Was there a yellow calendar in Qin and Han Dynasties?

There was no Gregorian calendar in ancient China. GM is now called the Gregorian calendar. China began to use the Gregorian calendar in the late Ming and early Qing dynasties, and it was spread by western missionaries. Tomb-Sweeping Day is a traditional folk festival in China, and it is one of the eight important festivals (Shangyuan Festival, Qingming Festival, Long Summer Festival, Dragon Boat Festival, Mid-Autumn Festival, Winter Solstice Festival and New Year's Eve). Generally speaking, it is around April 5th of Gregorian calendar, and the holiday period is very long. There are two kinds of sayings:/kloc-8 days before 0/0 and 10 days before 0/0. 108 The day after beginning of winter is Tomb-Sweeping Day. Tomb-Sweeping Day gas has a total of 15 days. As it is Tomb-Sweeping Day, the time is after the vernal equinox. "Almanac": "On the fifteenth day after the vernal equinox, the tripod is designated by the bucket, which means Qingming. When everything is clean and bright, when it is covered, everything is clean and bright, hence the name." As soon as Qingming comes, the temperature rises, which is a good time for spring ploughing and planting, so there is a saying that "melons and beans should be planted before and after Qingming". Tomb-Sweeping Day is a festival to worship ancestors, and the traditional activity is to sweep graves.