on; on top; upon; first (of two parts); previous or last (week etc); upper; higher; above; previous; to climb; to go into; above; to go up; to attend (class or university); third tone of putonghua[cedict]
时段
shí duànㄕˊ ㄉㄨㄢˋ
time interval; work shift; time slot; the twelve two hour divisions of the day[cedict]