Startup history

set pagesize 3000
set lines 300
col HOST_NAME format a30
col PLATFORM_NAME format a30
col STARTUP_TIME format a21
col DB_NAME format a9
select DBID
     , TO_CHAR(STARTUP_TIME, 'yyyy.mm.dd hh24:mi:ss') STARTUP_TIME
     , HOST_NAME
     , DB_NAME
     , PLATFORM_NAME
from DBA_HIST_DATABASE_INSTANCE
order by STARTUP_TIME;