The way the majority of the world measures age seems common sense to most people.
We are born without a year, and then every year on our birthday we get one year older. Simple right?
The Korean system isn’t so easy. In Korea, a baby is born being one year old because they include the time in the womb as being alive, so they are already technically a year older than westerners consider themselves. This may not seem so strange, but it gets odder.
Every New Year another year is added to their age. Thus, if a baby is born on the last day of the year, they will be two years old on New Year’s Day! Many do calculate their age according to Western culture because it’s much less complicated, yet this tradition is still popular in Korea.
The system was actually started in China and has been widely used across Asia throughout the years. It was officially outlawed in Japan, and fell out of use in most places. Korea, however, still favors this system over the Western one.