query: SELECT count(*) ,  time_of_day FROM broadcast GROUP BY time_of_day
question: how many program broadcast each times section day?
query_toks: SELECT count ( * ) , time_of_day FROM broadcast GROUP BY time_of_day
query_toks_no_value: select count ( * ) , time_of_day from broadcast group by time_of_day
question_toks: how many program broadcast each times section day?