Sanyang Kaitai is an idiom in China, which comes from China's ancient traditional cultural classics "Manner" and "Song Shi Le Zhi". This probably means that winter will pass and spring will come. In ancient China, Yang was homophonic with sheep, and sheep was Yang. Many auspicious inscriptions are written about "auspicious sheep", and generally it is written about Sanyang Kaitai.
During the Ming and Qing Dynasties, people used to call Qingyang, Hongyang and Baiyang the past, present and future respectively. The popular use of Sanyang Kaitai is an auspicious language, which indicates the significance of spring returning to the earth and the renewal of Vientiane, and also praises prosperity.