oracle8.1.6 select to_char(start_date, 'HH24:MI') as pretty_start_date, to_char(end_date, 'HH24:MI') as pretty_end_date, nvl(e.name, a.name) as name, e.event_id as item_id, c.calendar_name as calendar_name from acs_activities a, acs_events e, timespans s, time_intervals t, cal_items ci, calendars c where e.timespan_id = s.timespan_id and s.interval_id = t.interval_id and e.activity_id = a.activity_id and start_date between to_date(:current_date,:date_format) and to_date(:current_date,:date_format) + (24 - 1/3600)/24 and e.event_id = ci.cal_item_id and c.calendar_id = ci.on_which_calendar and c.calendar_id in ($list_of_calendar_ids) UNION select pretty_start_date, pretty_end_date, to_char(NULL) as name, 0 as item_id, to_char(NULL) as calendar_name from hours_of_the_day order by pretty_start_date