A law in South Korea will make people a year or two younger. The law was passed last Thursday. Before then, there were three ways people could tell their age. South Koreans had three ages. One was an "international age". This is how most people in the world calculate their age. A baby becomes one year old a year after it is born. The second was a "Korean age" – babies are a year old on the day they are born, and then a year is added every January the 1st. The third method was a "calendar age". Babies are zero years old at birth, and a year is added to their age every January the 1st.

The new law makes age in Korea simpler. It will end confusion about how old people are. From June, all official documents will use the international age. This will be the legal age for drinking, getting married, smoking, and military service. It will help to end the problems of the old system. However, some people will use the Korean age in informal situations. A Twitter user was happy with the simpler law. She tweeted: "I'll become two years younger.…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."