change the walltime for currently running PBS job (qalter pbs)

qalter jobid -l walltime=X

e.g.
qalter 377470.manager -l walltime=2222:00:00
qalter: Unauthorized Request  377470.manager

NOTE:

You cannot make any alterations to the executable portion of the script, nor can you make any changes after the job starts running.

Notes:

To alter requested resources for a currently queued (but not running) job use the qalter command.  You can change the wallclock limit, the account to be charged, email options, the stdout/stderr paths, and the total number of cores needed or the number of cores per node (mppnppn), among other things.  See the "qsub" man page for details. The two important restrictions are that you cannot change any attributes once your job begins running and you cannot change mppwidth so that the job moves across the execution queue boundaries.  Usage examples:

1.hopper% qalter -lwalltime=new_walltime jobid

2.hopper% qalter -lmppwidth=new_mppwidth jobid

REF:

https://www.nersc.gov/users/computational-systems/hopper/running-jobs/monitoring-jobs/

https://www.osc.edu/supercomputing/batch-processing-at-osc/monitoring-and-managing-your-job

http://torqueusers.supercluster.narkive.com/wWbtPk3E/can-i-add-to-the-walltime-of-a-running-job

http://stackoverflow.com/questions/8005906/is-there-a-way-to-change-the-walltime-for-currently-running-pbs-job

http://docs.adaptivecomputing.com/suite/8-0-1/basic/help.htm#topics/torque/commands/qalter.htm%3FTocPath%3DTORQUE%2520Resource%2520Manager%7CAppendices%7CAppendix%2520A%253A%2520Commands%2520Overview%7C_____7

http://www.supercluster.org/pipermail/torqueusers/2011-May/012919.html

https://wiki.hpcc.msu.edu/pages/viewpage.action?pageId=13863972

http://www.clusterresources.com/pipermail/torquedev/2013-October/004607.html