TSM backup results

select cast(entity as char(18)) Node, -
 cast(activity as char(6)) Task, -
 date(start_time) Date, -
 time(start_time) Time, -
 successful -
from summary -
 where activity='BACKUP' -
  and ( -
   (day(START_TIME)=day(current_timestamp)-1 and hour(start_time)>=18) -
  or -
   (day(START_TIME)=day(current_timestamp) and hour(start_time)<8) -
      ) -
order by START_TIME

the resualt of this script is start from 00:00:00 until 7:00

i need that the result will be from last day start in 8:00 until next day on 7:00

like between 31.5.2015 8:00 until 01.06.2015 7:00