Korean Days: 하루, 이틀, 사흘, 나흘...| Korean FAQ

The most common way to count days in Korean is using the counter 일 with Sino-Korean numbers (일, 이, 삼...), but there's also a second system that uses Pure Korean words (하루, 이틀, 사흘...). These aren't all necessary to learn, but you might want to know a few of them which are especially common.