A South Korean law will make people a year or two younger. Before the law, there were three ways people could tell their age. One was an "international age". A baby becomes one year old a year after it is born. The second was a "Korean age" – babies are a year old when they are born, and a year is added every January. The third method was a "calendar age". Babies are zero years old at birth, and a year is added every January.

The new law makes age in Korea simpler. All official documents will use the international age. This will be the legal age for drinking, getting married, and smoking. It will end the problems of the old system. However, some people will still use the Korean age. A woman was happy with the simpler law, and of being younger. She tweeted: "I turned two years old two weeks after I was born, as I was born in December. Finally, I'm about to get my real age back."