Get etime for all completed jobs

I am currently running

qstat -fx | grep etime

to get the etime for all jobs both current and past. Does PBS stores this information in lets say a log file which I can access to get this information or running thhe command is the only option for me?

You should be able to get the etime from the accounting logs:
source /etc/pbs.conf
cd $PBS_HOME/server_priv/accounting
grep etime -R *