The 3rd day of the 3rd lunar month is called Samjinnal. Samjil is the archaic word, and is also written as Sangsa, wonsa, Jungsam, sangjae, and dapchingchul in Chinese characters. Samjinnal implies the overlapping of Sam (three). According to Choi Namseon, samjil was derived from the consonants of Samil, and Sangsa is defined as the first snake day of the 3rd lunar month.
Samjinnal is the festive day that informs the arrival of spring. This day is known as the day the swallows came back from Gangnam and the day the snake came out from its winter sleep. It is also the day birds and butterflies start to appear. This day, in the North Gyeongsang region, seeing a snake signifies good luck, seeing a white butterfly means death that year, and seeing a yellow butterfly implies fortune. They say soybean paste brewed this day tastes especially good and houses are repaired. By conducting farm frugality, people pray for abundance.
During Samjinnal, people pick out azalea flowers and knead it with glutinous rice dough to make Hwajeon, a Korean traditional rice cake. Mung bean powder is used to make mung bean noodles, and is also occasionally used with the azalea flowers. By dyeing the mung bean powder with red water, a seasonal dish called Sumyeon can be prepared. Other than this, white bubble rice cakes made with red bean paste called Santteok, Goritteok made from glutinous rice, pine endodermis and mugwort, and Ssuktteok made from glutinous rice and mugwort leaves are eaten this day.