When I check the SLURM queue or my job status, I see:

"ReqNodeNotAvail, May be reserv"

Monthly maintenance downtimes are scheduled the first Tuesday of every month (unless otherwise noted) on the Academic (ub-hpc) and the Industry (presto) clusters.   Any jobs in the queue that can't finish before 7am the morning of the downtime won't run.  They will remain in the queue until the nodes are released back into production (usually by 5pm).

If you know your job could finish before the downtime begins, you can change the requested walltime in your script.  The default on both clusters is 72 hours and this is used if not specified in your SLURM script.  To specify a walltime other than 72 hours, add the following to your SLURM script:

#SBATCH --time=00:15:00

NOTE: time is in the format of  HOURS:MINUTES:SECONDS