Перевод времени в минуты : Oracle

select to_number(to_char(to_date('09:52','HH24:MI'),'SSSSS'))/60 from dual;

select (to_date('09:52','HH24:MI')-to_date('00:00','HH24:MI'))*1440 from dual;

select extract(hour from T)*60+extract(minute from T) from (select (interval '09:52' hour to minute) T from dual);

select to_char(to_date('09:52','HH24:MI'),'SSSSS')/60 from dual;