select id, event_time
from   table
order by to_char(sysdate+(to_timestamp(to_char(event_time,'MM/DD/YYYY')||' '||to_char(systimestamp,'HH24:MI'), 'MM/DD/YYYY HH24:MI')
+1-event_time),'HH24:MI') desc;

##</code><code>##

select id, event_time
from   table
order by to_char(systimestamp+1-event_time,'HH24:MI') desc;