On the Chinese luni-solar calendar, Dong Zhi / Winter Solstice is the 22nd solar term that will begin on Saturday, 22nd of December, 2018 at 06:22 Măo hour.
This is a day that has many related Chinese festive customs, as it usually signifies that winter has set in. In Singapore, it is usually a 拜拜 (prayer) day either to ancestors at the home prayer table or a trip to the temple. The food associated with this day are sticky chewy rice dumplings, usually eaten as a dessert in a sweet broth. In northern China, they eat steaming hot savoury dumplings. Given the cosmopolitan nature of the foodie culture these days, you can create your own festive Winter Solstice feast with a meal of dumplings followed by sticky rice balls dessert. The auspicious meaning of the dumplings is that of getting together, a reunion of family members.
Here is a simple explanation for those not familiar with technical terms. In the hexagram above, look at it as 6 layers stacked on top of each other. A whole line in one layer is Yang while a broken line in one layer is Yin. In the picture you can see the bottom line is Yang, while the 5 lines above are Yin. Simple, understand?