user_session_time1.htm
Reference : http://docs.oracle.com/cd/E11882_01/server.112/e40402/dynviews_3016.htm#REFRN30223
SQL query: In a SQL query V$SESSION provides session information for each current session.

 select username, to_char(logon_time,'DD-MM-YY HH:MI:SS')
FROM v$session
where username is not null;
 
Using php-query tool
OWNERID/SERVER :

Query: " select username, OWNERID, server, to_char(logon_time,'DD-MM-YY HH:MI:SS')FROM v$session where username is not null"