This is the 13190th most frequent Korean word.
둘째날
"둘째날" means "the second day."
Here, '둘째날' refers to the second day of a vacation, acting as a time marker.
휴가 둘째날에는 해변에서 놀았습니다.
On the second day of vacation, we played at the beach.
In this sentence, '둘째날' signifies the second day in the context of a volunteering activity.
그는 이번 봉사활동의 둘째날에 많은 사람들을 도왔어요.
He helped many people on the second day of this volunteering activity.
This usage of '둘째날' identifies the second day as a memorable time within the travel logs.