～時間目
～じかんめ · ～jikanme · JLPT N2 · noun
hour
🏫⏰ 時間 = time/hour, 目 = eye, used as an ordinal suffix: the hour-th, i.e. Nth period
時間 (jikan) means hour or time, and 目 (me) turns a count into an ordinal, as in 一つ目 (the first one). So 三時間目 is the third class period of the school day, not three hours.