Calculate the session how long it will be in idle State

Check the last activity time and how long the session in Idle state:

column SID format 999
column lastactivitytime format a25
column IdletimeinHrs format 9999999.99
select sid, to_char((sysdate - (hsecs - value)/(100606024)), 'dd-mon-yy hh:mi:ss') "Lastactivitytime" (hsecs - value)/(10060*60) "IdletimeinHrs"
from v$timer, v$sesstat
where statistic# = (select statistic# from v$statname
where name = 'process last non-idle time');

Query will be used to calculate the session idle time:

select st1.sid "SID", s.schemaname "User",
((sysdate - s.logon_time)*24*60*60) - (st1.value - st2.value) "Idle Time"
from
v$session s,
v$sesstat st1,
v$sesstat st2
where
s.sid = st1.sid and
s.sid = st2.sid and
st1.statistic# = (select statistic# from v$statname
where name = 'process last non-idle time') and
st2.statistic# = (select statistic# from v$statname
where name = 'session connect time');

Check the user last call or last activity after idle time:

LAST_CALL_ET that contains the number of seconds since the last call was made.

Select LAST_CALL_ET/60 "LastcallinMINS" from V$SESSION;