The other day talking with a co-worker the comment how to see the time when the database startup. I have to say in their defense that he has a lot of years of experience, although I also am. The issue is that he uses this statement;
DARMA*ANTO> SELECT MIN (LOGON_TIME) FROM V$SESSION WHERE 2 SERVICE_name ='SYS$BACKGROUND'; MIN(LOGON_TIME) ____________________ 13/ABR/2015 07:43:32
Formerly in versions 6 and 7 of Oracle such tricks they were very common. Currently to view an official way we can execute a select on the view v$instance. As shown in the following example.
DARMA*ANTO> select startup_time from v$instance; STARTUP_TIME ____________________ 13/ABR/2015 07:43:31
Another option, though perhaps more uncomfortable, is to look at alert.log
HTH – Antonio NAVARRO