noun
day duty; day shift; class duty
Refers to a person assigned to be on duty during the day, especially in schools (a student who helps the teacher) or workplaces. Often used with 〜をする or 〜になる.
今日は私が日直です。
I'm on day duty today.
日直の生徒が黒板を消した。
The student on class duty erased the blackboard.