S. Korean babies born Dec. 31 become 2-year-olds next day

In this April 9, 2019, photo, Lee Dong Kil's daughter Lee Yoon Seol sits to celebrate her the 100th day of the birth at Lee's house in Daejeon, South Korea. Just two hours after Lee’s daughter was born on New Year’s Eve, the clock struck midnight, 2019 was ushered in, and the infant became 2-years-old. She wasn’t alone, though it happened for her quicker than most: Every baby born in South Korea last year became 2 on Jan. 1.(AP Photo/Ahn Young-joon)

In this April 9, 2019, photo, Lee Dong Kil speaks with his wife Ryu Da Gyeong and daughter Lee Yoon Seol as they celebrate daughter Lee's the 100th day of the birth at their house in Daejeon, South Korea. Just two hours after Lee’s daughter was born on New Year’s Eve, the clock struck midnight, 2019 was ushered in, and the infant became 2-years-old. She wasn’t alone, though it happened for her quicker than most: Every baby born in South Korea last year became 2 on Jan. 1.(AP Photo/Ahn Young-joon)

DAEJEON, South Korea – Every baby born in South Korea last year was considered to be 2 on Jan. 1.

According to one of the world's most unusual age-calculating systems, South Koreans become 1 on the day of their birth and then get an additional year tacked on when the calendar hits Jan. 1.

A lawmaker is working now to overturn the centuries-old tradition amid complaints that it's an anachronistic, time-wasting custom that drags down an otherwise ultramodern country.

The origins of this age reckoning system aren't clear. Being 1 upon birth may be linked to the time babies spend in their mothers' wombs or to an ancient Asian numerical system that didn't have the concept of zero.