what are the names of the channels that broadcast in both morning and night?
select t1.name from channel as t1 join broadcast as t2 on t1.channel_id = t2.channel_id where t2.time_of_day = 'Morning' intersect select t1.name from channel as t1 join broadcast as t2 on t1.channel_id = t2.channel_id where t2.time_of_day = 'Night'